பொது அறிவு வினா-விடை – வரலாறு

 1. இரண்டாம் கர்நாடக போரின் முடிவில் கீழ்க்கண்ட ஒப்பந்தம் கையெழுத்தாயிற்று.
அ. அய்-லா-சாப்பேல் உடன்படிக்கை
ஆ. பாண்டிச்சேரி உடன்படிக்கை
இ. பாரிசு உடன்படிக்கை
ஈ. வட சர்க்கார் உடன்படிக்கை
2. கனிஷ்கரின் தலைநகர்
அ. காஷ்கர்
ஆ. யார்கண்டு
இ. பெஷாவர்
ஈ. எதுவுமில்லை
3. பொருத்துக:
I. கன்வ வம்சம் – 1. காட்பீசஸ்
II. சுங்க வம்சம் – 2. காரவேலர்
III. கலிங்க வம்சம் – 3. வசுதேவர்
IV. குஷான வம்சம் – 4. புஷ்ய மித்ரம்
அ. I-3 II-4 III-1 IV-2
ஆ. I-4 II-3 III-1 IV-2
இ. I-3 II-4 III-2 IV-1
ஈ. I-4 II-3 III-2 IV-1
4. பாண்டியர்களின் ஓவியக்கலை வளர்ச்சியை பறைசாற்றுவது
அ. மதுரை
ஆ. தொண்டி
இ. சித்தன்னவாசல்
ஈ. மானமாமலை
5. நாலந்தா பல்கலைக்கழகத்தின் துணை வேந்தராக இருந்தவர்
அ. ஹரிதத்தர்
ஆ. ஜெயசேனர்
இ. தர்மபாலர்
ஈ. எவருமில்லை
6. குஷானர்கள் எந்த நாட்டைச் சேர்ந்தவர்கள்
அ. கிரேக்கம்
ஆ. பாரசீகம்
இ. இந்தியா
ஈ. சீனா
7. தக்கர்களை ஒடுக்கிய ஆங்கிலேய ஆளுநர்?
அ. வில்லியம் பெண்டிங்
ஆ. காரன் வாலிஸ்
இ. வாரன் ஹேஸ்டிங்ஸ்
ஈ. டல்கௌசி
8. ‘புத்த தத்தர்’ யாருடைய காலத்தில் வாழ்ந்தார்
அ. கரிகாலன்
ஆ. இளஞ்சேரலாதன்
இ. அச்சுத களப்பாளன்
ஈ. தலையாலங்கானத்து செருவென்ற நெடுஞ்செழியன்
9. சோழர்களைப் பற்றி ஆய்வு செய்து எழுதியுள்ள வெனிசு வரலாற்று ஆசிரியர்
அ. அல்பருனி
ஆ. மார்க்கோ போலோ
இ. டாக்டர் ஜோன்ஸ் வில்லியம்
ஈ. இபன்படூடா
10. சமுத்திர குப்தனால் சிறை பிடிக்கப்பட்ட பல்லவ அரசன்
அ. பரமேஸ்வரவர்மன்
ஆ. விஷ்ணுகோபன்
இ. சிம்ம விஷ்ணு
ஈ. எவருமில்லை
விடை: 1. ஆ 2. இ 3. இ 4. இ 5. இ 6. ஈ 7. அ 8. இ 9. ஆ 10. ஆ
11. சாதவாகனா வம்சத்தின் சிறந்த அரசர் யார்?
அ. ஸ்ரீ சதகர்னி
ஆ. கௌதமிபுத்திர சதகர்னி
இ. வஷிஷ்டபுத்திர புலுமயி
ஈ. யஜ்னாஸ்ரீ சதகர்னி
12. மாவீரன் சிவாஜியின் தலைநகரம் எது?
அ. புனே
ஆ. கார்வார்
இ. புரந்தர்
ஈ. ராய்கார்
13. பண்டைய காலத்தில் கலிங்கத்தை ஆண்டவர்களில் யார் மிகப்பெரிய அரசராக கருதப்படுகிறார்?
அ. அஜாதசத்ரு
ஆ. பிந்துசாரர்
இ. காரவேலர்
ஈ. மயூரசரோனர்
14. பண்டைய இந்தியாவின் மிகச் சிறந்த மருத்துவராகக் கருதப்படும் தன்வந்திரி யாருடைய அரசவையில் ஆலோசனைகளை தந்து வந்தார்?
அ. சமுத்திரகுப்தர்
ஆ. அசோகர்
இ. சந்திரகுப்த விக்கிரமாதித்தியா
ஈ. கனிஷ்கர்

15. இரண்டாவது தரைன் யுத்தத்தில் பிருத்விராஜை தோற்கடித்தது யார்?
அ. கஜினி முகமது
ஆ. குத்புதீன் ஐபெக்
இ. கோரி முகமது
ஈ. அலாவுதீன் கில்ஜி
16. புத்தர் பிறந்த இடம் தற்போது உள்ள நாடு
அ. நேபாளம்
ஆ. திபெத்
இ. இந்தியா
ஈ. பர்மா

17. டெல்லியின் பழங்காலப் பெயர்
அ. தேவகிரி
ஆ. தட்ச சீலம்
இ. இந்திர பிரஸ்தம்
ஈ. சித்துபரம்
18. கீதகோவிந்தம் என்னும் நூலை எழுதியவர்
அ. ஜெயசந்திரன்
ஆ. ஜெயசேனர்
இ. ஹரிசேனர்
ஈ. எவருமில்லை
19. நாலந்த பல்கலைக்கழகத்தை தொடங்கியவர்
அ. குமார குப்தர்
ஆ. ஸ்கந்த குப்தர்
இ. ஹர்ஷர்
ஈ. யுவான் சுவாங்
20. ‘பரிவாதினி’ என்பது கீழ்க்கண்ட எதனுடன் தொடர்புடையது
அ. பல்லவர் ஓவியம்
ஆ. வீணை
இ. பல்லவர் கால நாடகம்
ஈ. மாமல்லபுரம் சிற்பம்
விடை: 11. ஆ 12. ஈ 13. இ 14. இ 15. இ 16. அ 17. இ 18. ஆ 19. அ 20. ஆ
31. மிகப்பெரிய கோயில்களை சாணக்கியர் கட்டிய இடங்கள்
அ. அய்ஹோலி
ஆ. ஹம்பி
இ. காஞ்சி
ஈ. வாதாபி
32. மாவீரர் அலெக்ஸாண்டரின் சம காலத்தவர் யார்?
அ. பிம்பிசாரர்
ஆ. சந்திரகுப்த மவுரியர்
இ. அசோகர்
ஈ. புஷ்யமித்ர சுங்கர்
33. சௌசா போர் யார் யாருக்கிடையே நடைபெற்றது?
அ. பகதூர் ஷா மற்றும் ஹுமாயூன்
ஆ. ஹுமாயூன் மற்றும் ஷெர்கான்
இ. அக்பர் மற்றும் ராணா பிரதாப்
ஈ. ஜஹாங்கீர் மற்றும் ராணா அமர் சிங்
34. அமெரிக்க சுதந்திர பிரகடனத்தை வடிவமைத்தவர் யார்?
அ. வாஷிங்டன்
ஆ. பெஞ்சமின் பிராங்க்ளின்
இ. தாமஸ் ஜெபர்சன்
ஈ. கால்வின் கூலிட்ஜ்
35. புத்த மத இலக்கியங்கள் எந்த மத மொழியில் எழுதப்பட்டன?
அ. ஒரியா
ஆ. சமஸ்கிருதம்
இ. உருது
ஈ. பாலி
36 ஹொய்சால மன்னரை மதம் மாற்றிய இந்து மத தத்துவவாதி யார்?
அ. ராமானுஜர்
ஆ. ஆதிசங்கரர்
இ. சங்கராச்சாரியார்
ஈ. சுவாமி விவேகானந்தர்
37. மகாபலிபுரத்தில் ஒரே கல்லில் உருவாக்கப்பட்ட ரதங்கள் எத்தனை உள்ளன?
அ. 2
ஆ. 3
இ. 5
ஈ. 19
38. பண்டைய இந்திய வரலாற்று புவியியலில் ரத்னாகரா என வழங்கப்பட்டது எது?
அ. இமயமலை
ஆ. அரபிக் கடல்
இ. இந்தியப் பெருங்கடல்
ஈ. இவை எதுவும் இல்லை
39. ரத்னாவளியை இயற்றியவர்
அ. கனிஷ்கர்
ஆ. வால்மீகி
இ. ஹர்ஷர்
ஈ. ஹரிஹரபுக்கர்
40. ரஸியா சுல்தானைப் பற்றிய பின்வரும் தகவல்களில் எது சரி?
அ. தில்லியை ஆண்ட ஒரே முஸ்லிம் பெண்மணி
ஆ. சதியால் கொல்லப்பட்டவர்
இ. 1240ல் கைதாள் என்னும் இடத்தில் கொல்லப்பட்டார்
ஈ. இவை அனைத்தும் சரி
விடை: 31. அ 32. ஆ 33. ஆ 34. இ 35. ஈ 36. அ 37. இ 38. ஆ 39. இ 40. ஈ
41. ரக்திகா என்பது
அ. பண்டைய இந்தியாவின் கலைப் பிரிவு
ஆ. பண்டைய இந்தியாவின் ஓவியப் பிரிவு
இ. பண்டைய இந்தியாவின் எடை முறை
ஈ. இவை எதுவும் சரியல்ல
42. கல்ஹானா என்பவர் எழுதிய ராஜதரங்கிணி என்னும் புத்தகம் எதைப் பற்றியது?
அ. மாவீரர் சிவாஜி பற்றியது
ஆ. காஷ்மீரின் வரலாற்றைப் பற்றியது
இ. நமது வேதங்களைப் பற்றியது
ஈ. இவை அனைத்துமே சரி
43. களப்பிறர் காலத்தில் தமிழகத்தில் அறிமுகப்படுத்தப்பட்ட மொழி
அ. சமஸ்கிருதம்
ஆ. பிராக்கிருதம்
இ. தெலுங்கு
ஈ. இவை அனைத்தும்
44. கஜுராகோ விஷ்ணு கோயிலைக் கட்டியவர்
அ. தாங்கர்
ஆ. கீர்த்திவர்மன்
இ. யசோதவர்மன்
ஈ. உபேந்திரர்
45. கற்கால மனிதன் முதலில் கற்றுக் கொண்டதாக கருதப்படுவது
அ. தீயினை உருவாக்க
ஆ. விலங்குகளை வளர்க்க
இ. சக்கரங்களை செய்ய
ஈ. தானியங்களை வளர்க்க
46. புத்த சமயத்தின் அடிப்படை கொள்கை
அ. தியானம்
ஆ. அறியாமை அகற்றுதல்
இ. நோம்பு
ஈ. திருடாமை
47. மௌரியர் காலத்தின் மிக உயர்ந்த நீதிமன்றமான அரசமன்றத்தின் அமைவிடம்
அ. கபில வஸ்து
ஆ. சாரநாத்
இ. கோசலம்
ஈ. பாடலிபுத்திரம்
48. ஹர்ஷ சரிதம் எழுதியவர்
அ. ஹர்ஷர்
ஆ. பாணர்
இ. ஹரிசேனர்
ஈ. தர்மபாலர்
49. சரக சமிதம் என்பது
அ. வானவியல் நூல்
ஆ. புத்த இலக்கியம்
இ. மருத்துவ நூல்
ஈ. கணித நூல்
50. நான்காம் புத்த சமய மாநாடு கூட்டப்பட்ட இடம்
அ. குந்தல்வனம்
ஆ. பெஷாவர்
இ. கனிஷ்கபுரம்
ஈ. கோட்டான்
விடை: 41. இ 42. ஆ 43. ஆ 44. இ 45. அ 46. ஆ 47. ஈ 48. ஆ 49. இ 50. அ
51. போரில் உயிர்நீத்த வீரர்கள் நினைவாக நடப்பட்ட வீரகற்கள்
அ. பெருங்கல்
ஆ. நடுகல்
இ. வீரக்கல்
ஈ. கல்பாடிவீடு

52. முறையான எழுத்து முறை எதில் உருவானது?
அ. ஆரியர் காலம்
ஆ. சுமேரிய நாகரீகம்
இ. சிந்து சமவெளி நாகரீகம்
ஈ. எகிப்து நாகரீகம்
53. அலாவுதீன் கில்ஜியின் தந்தை
அ. கியாசுதீன்
ஆ. குத்புதீன்
இ. ஜலாலுதீன்
ஈ. நசுருதீன்
54. தோடர்மால் யாருடைய அவையிலிருந்த வருவாய் அமைச்சர்?
அ. ஜஹாங்கீர்
ஆ. அவுரங்கசீப்
இ. அக்பர்
ஈ. ஷாஜகான்
55. கீழ்க்கண்ட மன்னர்களை சரியான வரிசையில் எழுதுக
1. பெரோஷ் துக்ளக்
2. ஜலாலுதீன் கில்ஜி
3. பகலால் லோடி
4. சிக்கந்தர் லோடி
அ. 1, 2, 3, 4
ஆ. 2, 1, 3, 4
இ. 1, 2, 4, 3
ஈ. 2, 1, 4, 3
56. திரிபீடகங்கள் என்பது யாருடைய புனித நூல்?
அ. சமண மதம்
ஆ. புத்த மதம்
இ. இந்து மதம்
ஈ. கிறிஸ்தவ மதம்
57. கி.பி. 505 முதல் 587 வரையிலான காலத்தில் வாழ்ந்த மற்றும் விக்கிரமாதித்யன் அவையிலிருந்த வராகமித்திரர் ஒரு
அ. வானியல் நிபுணர்
ஆ. கணித மேதை
இ. தத்துவஞானி
ஈ. இவை அனைத்துமே
58. முகமது பின் துக்ளக் தலைநகரை தில்லியிலிருந்து தேவகிரிக்கு மாற்றிய ஆண்டு
அ. 1319
ஆ. 1327
இ. 1339
ஈ. 1345
59. வேத காலம் என்பது
அ. கி.மு. 1500 முதல் கி.மு. 1000 வரை
ஆ. கி.மு. 1000 முதல் 500 வரை
இ. கி.மு. 500 முதல் 100 ஆண்டுகள்
ஈ. இவை எதுவும் இல்லை
60. முஸ்லிம் அல்லாதவரிடம் விதிக்கப்பட்ட ஜஸியா வரியை அறிமுகப்படுத்தியவர் யார்?
அ. அக்பர்
ஆ. ஜஹாங்கீர்
இ. அவுரங்கசீப்
ஈ. அலாவுதீன் கில்ஜி
விடை: 51. ஆ 52. ஆ 53. இ 54. இ 55. ஆ 56. ஆ 57. ஈ 58. ஆ 59. அ 60. ஈ
61. அங்கோர்வாட் கலைக்கோவில்கள் எங்குள்ளன?
அ. பிலிப்பைன்ஸ்
ஆ. தாய்லாந்து
இ. கம்போடியா
ஈ. வியட்னாம்

62. தயானந்த சரஸ்வதியால் உருவாக்கப்பட்ட ஆரிய சமாஜம் பற்றி எது சரி?
அ. உருவ வழிபாட்டை ஏற்றுக் கொண்டது
ஆ. இந்து மதத்திற்கு மதமாற்றம் செய்து கொள்வதை ஆதரித்தது
இ. ஜாதி முறையை கண்டித்தது
ஈ. அவை அனைத்துமே சரி
63. இல்டுட் மிஷ் காலத்தில் எல்லை அபாயங்களை ஏற்படுத்தியவர்
அ. தைமூர்
ஆ. செங்கிஸ்கான்
இ. பெரோஷ் துக்ளக்
ஈ. அனைவரும்
64. முகமதுகோரி கஜினியைக் கைப்பற்றிய ஆண்டு
அ. 1173
ஆ. 1174
இ. 1175
ஈ. 1176
65. பின்வருவனவற்றில் ஆரியர்களைப் பற்றி எது சரியான தகவல்?
அ. இவர்கள் மத்திய ஆசியாவிலிருந்து வந்தவர்கள்
ஆ. மாடு மேய்ப்பது இவர்களின் முக்கியத் தொழில்
இ. இவர்களுக்கு பசு புனிதமான வடிவம்
ஈ. இவை அனைத்துமே சரி

66. அசோக சக்கரவர்த்தியைப் பற்றி எது சரியான கூற்று?
அ. கி.மு. 269 முதல் 232 வரை ஆட்சி புரிந்தார்
ஆ. கலிங்கப் போருக்குப் பின் போரை வெறுத்து புத்த மதத்தைத் தழுவினார்
இ. இவரது மறைவுக்குப் பின் மௌரியப் பேரரசு வீழ்ச்சி அடையத் தொடங்கியது
ஈ. இவை அனைத்தும் சரி

67. அஷ்ட பிரதானிகள் யாருடைய அவையில் இருந்த அறிஞர்கள்?
அ. அசோகர்
ஆ. சிவாஜி
இ. கனிஷ்கர்
ஈ. சந்திரகுப்தர்
68. சாக்கிய முனி என அழைக்கப்பட்டவர் யார்?
அ. ராமகிருஷ்ண பரமஹம்சர்
ஆ. மகாவீரர்
இ. கௌதம புத்தர்
ஈ. விவேகானந்தர்
69. சுஸ்ருதா என்னும் நூல் எதோடு தொடர்புடையது?
அ. நிலவரி
ஆ. அரசின் வருமான வரி
இ. வானியல்
ஈ. மருத்துவம்

70. சோழர்கள் ஆட்சியின் சிறப்பு என்ன?
அ. தஞ்சாவூர் கோயிலை கட்டிய சோழர் கால கலை
ஆ. கிராம சுயாட்சி
இ. சிறப்பான உள்ளாட்சி முறை
ஈ. இவை அனைத்துமே
விடை: 61. இ 62. ஈ 63. ஆ 64. அ 65. ஈ 66. ஈ 67. ஆ 68. இ 69. ஈ 70. ஈ
71. ஆர்ய சத்யா என்னும் உபதேசங்களில் புத்தர் எதைப் பற்றிக் கூறுகிறார்?
அ. துன்பம்
ஆ. துன்பத்திற்கான காரணம்
இ. துன்பத்தை களைவது
ஈ. இவை அனைத்தையும்

72. அலெக்ஸாண்டர் இந்தியா மீது படையெடுத்தது எப்போது?
அ. கி.மு. 310
ஆ. கி.மு. 342
இ. கி.மு. 362
ஈ. கி.மு. 326
73. அமிர்தசரஸ் நகரத்திற்கான இடம் யாரால் குரு ராம் தாசுக்குத் தரப்பட்டது?
அ. ஹர்ஷர்
ஆ. பாபர்
இ. அக்பர்
ஈ. ஹுமாயூன்

74. கவுடில்யர் எழுதிய அர்த்தசாஸ்திரம் எத்தனை பகுதிகளைக் கொண்டது?
அ. 10
ஆ. 2
இ. 5
ஈ. 15
75. விக்ரம சீவப் பல்கலைகழகத்தை நிறுவியவர்
அ. ஹர்ஷர்
ஆ. தர்மபாலன்
இ. தேவபாலன்
ஈ. எவருமில்லை

76. அசோகரது கல்வெட்டுக்களில் அவரது அண்டை பகுதியினர் என யாரை குறிப்பிடுகிறார்?
அ. பாண்டியர்கள்
ஆ. கேரளாபுத்திரர்கள்
இ. சத்யபுத்திரர்கள்
ஈ. இவர்கள் அனைவரையும்
77. சித்தாந்த சிரோமணி என்னும் நூலை எழுதியவர் யார்?
அ. பாஸ்கரவர்மன்
ஆ. பாஸ்கராச்சாரியர்
இ. பத்ரபாகு
ஈ. பில்கானா
78. புத்த மதத்திற்கும் சமண மதத்திற்குமான பொதுவான அம்சம் யாது?
அ. வேதங்களின் கருத்துக்களை மறுத்தது
ஆ. சடங்குகளை மறுத்தது
இ. விலங்குகள் கொல்லப்படுவதை எதிர்த்தது
ஈ. இவை அனைத்துமே
79. முதல் உலகப் போரின் முக்கிய காரணம் என்ன?
அ. லாயிட் ஜார்ஜின் திடீர் மரணம்
ஆ. லெனின் சிறை வைப்பு
இ. ஆஸ்திரியாவின் பிரான்சிஸ் பெர்டினான்ட் படுகொலை செய்யப்பட்டது
ஈ. உலகை ஆள அமெரிக்கா விரும்பியது
80. பின்வரும் எந்த அரசு பீகாரில் ஆட்சி புரிந்தது?
அ. வஜ்ஜி
ஆ. வத்சா
இ. சுராசேனா
ஈ. அவந்தி
விடை: 71. ஈ 72. ஈ 73. இ 74. ஈ 75. இ 76. ஈ 77. ஆ 78. ஈ 79. இ 80. அ
81. பல்லவ மன்னர்களின் தலை நகரமாக எது விளங்கியது?
அ. சென்னப்பட்டினம்
ஆ. காஞ்சிபுரம்
இ. மதுரை
ஈ. மகாபலிபுரம்
82. களப்பிரர்களின் காலம் எது?
அ. ஒன்று முதல் 3ம் நூற்றாண்டு
ஆ. 3 – 6ம் நூற்றாண்டு
இ. 5 – 8ம் நூற்றாண்டு
ஈ. இவை எதுவுமில்லை

83. யாருடைய ஆட்சியில் வர்த்தமான மகாவீரர் மற்றும் கௌதம புத்தர் ஆகியோர் தங்களது உபதேசங்களை மேற்கொண்டனர்?
அ. அஜாத சத்ரு
ஆ. பிம்பிசாரர்
இ. நந்திவர்த்தனர்
ஈ. அசோகர்
84. யாருடைய காலத்தில் கிராம சமூகம் அதிக அதிகாரங்களைப் பெற்றிருந்தது?
அ. பல்லவர்கள்
ஆ. சோழர்கள்
இ. குப்தர்கள்
ஈ. முகலாயர்கள்
85. சுதந்திரப் போரின் போது அமெரிக்காவில் எத்தனை காலனிகள் இருந்தன?
அ. 14
ஆ. 13
இ. 15
ஈ. 12

86. கி.பி. 1451 வரை இந்தியாவை ஆண்ட அரசர்கள் எந்த இனத்தை சார்ந்தவர்கள்?
அ. துருக்கியர்
ஆ. அரேபியர்
இ. பதானியர்
ஈ. ஆப்கானியர்
87. தைமூர் இந்தியாவிற்குள் படையெடுத்த ஆண்டு
அ. 1326
ஆ. 1349
இ. 1372
ஈ. 1398
88. ‘அல்பரூனி’ யாருடன் இந்தியா வந்தார்
அ. முகமது கஜினி
ஆ. முகமது கோரி
இ. முகமது பின் காசிம்
ஈ. தைமூர்
89. கீழ்க்கண்டவற்றில் எது சரியாக பொறுத்தப்படவில்லை
அ. கன்னோசி – பிரதிகாரர்கள்
ஆ. ஆஜ்மீர் – சவுக்கான்கள்
இ. சந்தேளர்கள் – பந்தல்கண்ட்
ஈ. பாளர்கள் – டெல்லி

90. சுங்கம் தவிர்த்த சோழன் என்று அழைக்கப்படுபவர்
அ. முதலாம் ராஜராஜன்
ஆ. முதலாம் குலோத்துங்கன்
இ. முதலாம் ராஜேந்திரன்
ஈ. இரண்டாம் ராஜராஜன்
விடை: 81. ஆ 82. ஆ 83. ஆ 84. ஆ 85. ஆ 86. அ 87. ஈ 88. அ 89. ஈ 90. ஆ
91. மயில் சிம்மாசனம் எந்த அரசருக்காக உருவாக்கப்பட்டது?
அ. ஹுமாயூன்
ஆ. ஷாஜகான்
இ. அக்பர்
ஈ. நாதிர் ஷா
92. ஆரிய சமாஜ இயக்கத்தை தொடங்கியது யார்?
அ. ரவீந்திர நாத் தாகூர்
ஆ. ராஜாராம் மோகன் ராய்
இ. சுவாமி தயானந்தர்
ஈ. கேசாப் சந்திர சென்
93. ஔரங்கசீப்பால் தூக்கிலிடப்பட்ட சீக்கிய குரு யார்?
அ. குரு அர்ஜுன் தேவ்
ஆ. குரு ஹர்கோவிந்த்
இ. குரு ஹர்கிஷன்
ஈ. குர் தேஜ் பகதூர்

94. மன்சப்தாரி முறையை அறிமுகப்படுத்தியவர் யார்?
அ. அலாவுதீன் கில்ஜி
ஆ. ஷெர்ஷா சூரி
இ. பாபர்
ஈ. அக்பர்

95. அக்பரின் அவையிலிருந்த நவரத்தினங்களில் இந்தி கவிஞர் யார்?
அ. அபுல் பாசல்
ஆ. பைசி
இ. அப்பாஸ் கான் ஷெர்வானி
ஈ. பீர்பால்
96. பதவிக்கு வரும் போது அக்பரின் வயது என்ன?
அ. 11 வயது
ஆ. 14 வயது
இ. 12 வயது
ஈ. 17 வயது
97. அக்பருக்கு குழந்தை பாக்கியத்தை அருளியவர் என நம்பப்படுகிற, பதேபூர் சிக்ரியில் அடக்கம் செய்யப்பட்டிருக்கும் சூபி துறவி யார்?
அ. ஷேக் பக்ரித்
ஆ. நிஜாமுதீன் அவுலியா
இ. சலிம் சிஸ்டி
ஈ. ஷேக் பக்டியார் காக்கி

98. தற்போது ஹம்பி என அழைக்கப்படும் விஜயநகரம் எந்த நதிக்கரையில் அமைந்திருக்கிறது?
அ. கிருஷ்ணா
ஆ. காவேரி
இ. துங்கபத்ரா
ஈ. கோதாவரி

99. விஜயநகரப் பேரரசை நிறுவியவர் யார்?
அ. இரண்டாம் ஹரிஹரர்
ஆ. விஜய ராயர்
இ. இரண்டாம் புக்கர்
ஈ. ஹரிஹரர், புக்கர்
100. தன்னை காலிப் என அழைத்துக் கொண்ட ஒரே சுல்தான் யார்?
அ. அலாவுதீன் கில்ஜி
ஆ. முபாரக் ஷா கில்ஜி
இ. குஸ்ரு ஷா
ஈ. முகமது பின் துக்ளக்
விடை: 91. ஆ 92. இ 93. ஈ 94. ஈ 95. ஆ 96. ஆ 97. இ 98. இ 99. ஈ 100. ஆ

Chemistry videos

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Chemistry videos - chemicum.com

In order to make chemistry lessons more interesting, 111 chemistry videos are being developed by scientists and lecturers from Chemicum of University of Tartu, Estonia. "100+ Experiments in Chemistry" is designed for chemistry teachers for showing commented experiment videos in front of classroom. In addition to a school programme, some interesting chemistry phenomena is explained: Caesium reaction with water was filmed with the help of a bomb group. What is cold light or chemiluminescence. Thermoreactive compounds change color upon heating. Very odd reaction - "The Pharaoh's Serpent". Nitrocellulose explodes and puts formula model car on the move. Why pyrophoric iron, silane and white phosphorus ignite spontaneously. Some magic - clock reaction and magical color changes. What is the working principle of batteries, fuel cells and supercapacitors and how to prepare these yourself? What makes fireworks colorful (green, red, yellow)? Time fuse can be used for igniting safely some pyrotechnic mixtures, for example aluminothermic mixture or "Vulcano". Let's prepare a color changing flower and some chemical seaweed.

DIY electrochemistry experiments. New! Kemizoo free molecule viewer is online (introduction).

NON-METALS: ->Reactions with oxygen: 1. Preparation and verification of oxygen 2. Combustion of coal in melted potassium nitrate 3. Combustion of sulphur in melted potassium nitrate 4. Combustion of coal in air and oxygen 5. Combustion of sulphur in air and oxygen 6. Combustion of red phosphorus in air and oxygen 7. Self-ignition of white phosphorus in air 8. Electrolysis of water 9. Changes in pH during water electrolysis
->Reactions with hydrogen: 10. Preparation and combustion of hydrogen 11. Lightness of hydrogen 12. Reduction of copper(II)oxide with hydrogen
->Reactions with carbon dioxide: 13. Carbon dioxide as heavier gas than air 14. Preparation of CO2 from copper- hydroxidecarbonate 15. Carbon dioxide as a fire-extinguisher 16. Carbon dioxide in exhaled air 17. Preparation of carbon dioxide from a vitamine pill 18. Preparation of CO2 from lime scale and acetic acid 19. Preparation of carbon dioxide from carbonated water 20. Carbon dioxide reaction with alkali 21. pH change in the dissolution of carbon dioxide 22. Experiments with solid carbon dioxide 23. Combustion of magnesium in carbon dioxide
->Reactions with nitrogen and ammonia: 24. Nitrogen as a fire-extinguisher 25. Preparation of ammonia and dissolution in water 26. pH change in the dissolution of ammonia
->Reactions with chlorine: 27. Reaction between ammonia and hydrogen chloride 28. Preparation and verification of chlorine 29. Reaction of chlorine and iodide 30. Photochemical reaction: chlorine and hydrogen 31. Combustion of sodium in chlorine 32. Reaction of chlorine and copper 33. Combustion of antimony in chlorine 34. Reaction of chlorine and iron
METALS: ->s_metals: 35. Reaction of sodium and water 36. Reaction of lithium and water 37. Reaction of potassium and water 38. Reaction of calcium and water 39. Reaction of sodium and sulphur 40. Burning of magnesium
->p,d_metals: 41. Burning of iron powder 42. Burning of zinc powder 43. Aluminothermy 44. Reaction of aluminium and alkali 45. Reaction of iron and sulphur 46. Reaction of zinc and iodine 47. Reaction of zinc and acids 48. Reaction of copper and nitric acid 49. Deposition of copper on iron 50. Deposition of mercury on copper
->Flame tests: 51. Flame-test of a sodium salt 52. Flame-test of a potassium salt 53. Flame-test of a lithium salt 54. Flame-test of a barium salt 55. Flame-test of a strontium salt 56. Flame-test of copper
Characteristics of reactions: 57. Charateristics of a chemical reaction 58. Color changes 59. Evolution of gas 60. Formation of insoluble compound 61. Generation of light 62. Sound effect 63. Release of heat 64. Absorption of heat 65. The Pharaoh's Serpent
Separation of mixtures: 66. Filtration 67. Vacuum filtration 68. Separation of immiscible liquids 69. Sublimation 70. Distillation 71. Centrifugation 72. Chemical purification of gasses
Reaction rate, equilibrium: 73. The effect of concentration on rate of reaction 74. Dependence of reaction rate on primary substance 75. Temperature influence on chemical equilibrium 76. Chromium(III)oxide as a catalyst 77. Water ignites fire
Solutions, pH: 78. Influence of mixing on the speed of dissolution 79. Temperature dependence of salt solubility 80. Solubility of a gas 81. The color scale of universal indicator 82. Strong and weak acids and bases 83. Determination of pH for consumer goods 84. pH of salt solutions, hydrolysis 85. Basic oxide reaction with water 86. Magical color changes
Experiments with organic compounds: 87. Burning of carbohydrates 88. Burning of alcohols 89. Reaction of sodium and ethanol 90. Reaction of sulphuric acid and carbohydrates 91. Combustion of nitrocellulose 92. Combustion of boric acid ethyl ester 93. Chemiluminescence 94. Time fuse
Electrochemistry: 95. Chemical current source 96. Hydrogen-oxygen fuel cell 97. Storing wind energy in hydrogen 98. Storing solar energy in hydrogen 99. Tic-Tac supercapacitor 100. Electrochemical deposition of copper
Demonstration videos: 101. Reaction of rubidium and water 102. Reaction of caesium and water 103. Thermoreactive compounds 104. Volcano 105. Oxidizing properties of manganese(VII) oxide 106. Preparation and combustion of silane 107. Chemical clock 108. Fire as an artist 109. Silicate garden 110. Pyrophoric iron 111. Combustion in potassium chlorate

The Core

• Algebra
• Analysis
• Partial Differential Equations
• Geometry & Topology
• Discrete Mathematics
• Applied Mathematics
• Probability Theory

The Core

Analytical Chemistry
Biological Chemistry
Inorganic Chemistry
Organic Chemistry
Physical Chemistry
Theoretical Chemistry

Ligands

Ligands are ions or neutral molecules that bond to a central metal atom or ion. Ligands act as Lewis bases (electron pair donors), and the central atom acts as a Lewis acid (electron pair acceptor). Ligands have at least one donor atom with an electron pair used to form covalent bonds with the central atom. Ligands can be anions, cations, or neutral molecules.

Monodentate Ligands

A monodentate ligand has only one donor atom used to bond to the central metal atom or ion. The term "monodentate" can be translated as "one tooth," referring to the ligand binding to the center through only one atom. Some examples of monodentate ligands are: chloride ions (referred to as chloro when it is a ligand), water (referred to as aqua when it is a ligand), hydroxide ions (referred to as hydroxo when it is a ligand), and ammonia (referred to as ammine when it is a ligand).

        

                 Fig. 1. Central atom with six monodentate ligands attached. (Image courtesy of Wikimedia Commons.)   

Bidentate Ligands

Bidentate ligands have two donor atoms which allow them to bind to a central metal atom or ion at two points. Common examples of bidentate ligands are ethylenediamine (en), and the oxalate ion (ox). Shown below is a diagram of ethylenediamine: the nitrogen (blue) atoms on the edges each have two free electrons that can be used to bond to a central metal atom or ion.

Fig. 2. Ethylenediamine an example of a bidentate ligand. (Image courtesy of Wikimedia Commons.)

Polydentate Ligands

Polydentate ligands range in the number of atoms used to bond to a central metal atom or ion. EDTA, a hexadentate ligand, is an example of a polydentate ligand that has six donor atoms with electron pairs that can be used to bond to a central metal atom or ion.

EDTA is a polydentate ligand. (Image courtesy of Wikimedia Commons.)

Chelation

Chelation is a process in which a polydentate ligand bonds to a metal ion, forming a ring. The complex produced by this process is called a chelate, and the polydentate ligand is referred to as a chelating agent.

Metal-EDTA Chelate. (Image courtesy of Wikimedia Commons.)

Ligand Nomenclature

For a more in-depth study of ligand nomenclature, read the module on Nomenclature of Coordination Complexes

1. If a complex has an ion ligand, an "-o" ending is added. For example, "-ide" is changed to "-o," "-ite" is changed to "-ito", and "-ate" to "-ato." Hence, the bromide ion (Br^-) becomes bromo, the nitrite ion (NO₂^-) becomes nitrito, and the sulfate ion (SO₄^2-) becomes sulfato.
2. When a complex has a neutral molecule ligand, the molecule keeps its original name. For example, ethylenediamine is a ligand, and the ligand is still called ethylendiamine.
3. Prefixes mono=1, di=2, tri=3, tetra=4, penta=5, and hexa=6, are used to specify the number of ligands. If a ligand name has a prefix within itself such as ethylendiamine, place a parenthesis around the name and add bis=2, tris=3, tetrakis=4, in front of the molecule. For example, if there was 2 (en) molecules, the name would be bis(ethylenediamine).
4. When naming a complex, ligands are the first to be named. If there is more than one ligand, list them in alphabetical order. Next comes the metal ion or atom. The oxidation state follows the name in roman numerals.                                    

Problems

1. Do ligands act like Lewis acids or Lewis bases? Why?
2. Do ligands form ionic bonds with the central metal atom?
3. What are chelating agents?
4. What is a monodentate ligand?
5. Describe polydentate ligands and provide an example.
6. What are hexadentate ligands?
7. Name this complex [Cu(NH₃)₄]SO₄.
8. Name this complex  [Co(en)₃](NO₃)₂.

Answers

1. Ligands act like Lewis bases because they share their electron pairs (electron donors) with the central metal atom.
2. No, ligands do not form ionic bonds the with the central metal atom. Rather, they form covalent bonds with the central metal atom because they share electron pairs.
3. Chelating agents are ligands that have two or more atoms with donating electron pairs that are able to attach a metal ion at the same time. These chelating ligands are monodentate and tridentate ligands
4. A monodentate ligand is a ligand that uses only one pair of electrons to bond to the central metal atom or ion.
5. Polydentate ligands are ligands which are able to donate more than two electron pairs to the central metal they bond to. EDTA is an example of a polydentate ligand.
6. Hexadentate ligands are ligands which have six lone pairs of electrons which can all bond to the central metal atom.
7. tetraamminecopper(II) sulfate
8. Tris(ethylenediamine)cobalt(II) nitrate

References

1. Petrucci, Harwood, Herring, Madura. General Chemistry Principles & Modern Applications. Prentice Hall. New Jersey, 2007
2. Cox, Tony. (2004). Instant notes in inorganic chemistry. Oxford, UK: Taylor & Francis.
3. Libraries, Association, Robert Williams, and J. Silva. Bringing chemistry to life. Oxford University Press, USA, 1999. Print.
4. Moeller, Therald, Douville, Judith, & Libraries, Association. (1988). Inorganic Chemistry: A Modern Introduction. Amer Library Assn.
5. Bowker, R., Warmus, Mieczysław, Muzzy, Adrienne, LOCALIZADO, AUTOR, Hopkinson, Barbara, Saur, K, Izod, Irene, Hopkinson, Barbara, Saur, K, Books, K, & Company, K. (1994). Inorganic Chemistry Concepts. K G Saur Verlag Gmbh & Co.
6. Porterfield, William. (1984). Inorganic chemistry. Addison Wesley Publishing Company.

Outside Sources

1. Electronic Structure of Coordination Complexes http://www.youtube.com/watch?v=mAPFhZpnV58
2. Transition Metal Complexes http://www.youtube.com/watch?v=UvWBuryKlSk&feature=related
3. Coordination Complexes A http://www.youtube.com/watch?v=v7MbkMi3aMQ&feature=related
4. Coordination Complexes B http://www.youtube.com/watch?v=nYHHpONul80&feature=related
5. Molecular docking simulation: multiple ligand simultaneous docking http://www.youtube.com/watch?v=oeqJo9xYviY
6. Identification of Ligands for Protein Purification http://www.youtube.com/watch?v=429j3Ikxxy0
7. In Scopus. "ScienceDirect - Analytical Biochemistry : LIGAND: A Versatile Computerized Approach for Characterization of Ligand-binding Systems." ScienceDirect - Home. Web. 02 June 2010. <http://www.sciencedirect.com/science...b01ccf162fea5e>.
8. "Systematic Evolution of Ligands by Exponential Enrichment: RNA Ligands to Bacteriophage T4 DNA Polymerase -- Tuerk and Gold 249 (4968): 505 -- Science." Science/AAAS | Scientific Research, News and Career Information. Web. 02 June 2010. <http://www.sciencemag.org/cgi/conten...i;249/4968/505>.
9. "Differential Ligand Activation of Estrogen Receptors ER{alpha} and ER at AP1 Sites -- Paech Et Al. 277 (5331): 1508 -- Science." Science/AAAS | Scientific Research, News and Career Information. Web. 02 June 2010. <http://www.sciencemag.org/cgi/conten.../277/5331/1508>.
10. Green, M.L.H. A new approach to the formal classification of covalent compounds of the elements. (1995) Journal of Organometallic Chemistry

How to Make Limewater

 

The saturated solution of calcium hydroxide is referred to as limewater. It should not be confused with the acidic fruit lime or with lemon water. In other words, limewater is a clear, colorless, aqueous solution of calcium hydroxide. It is made by mixing calcium hydroxide in water (4 to 8 times the quantity of lime). The term can be used to refer to water that contains dissolved lime or calcium salts.

The solubility of hydroxides in water increases as we go down the group. Calcium hydroxide is less soluble in comparison to barium hydroxide. 1 liter of pure water can dissolve about 1 gram of calcium hydroxide.

Properties

Limewater has an earthy smell
It tastes of calcium hydroxide (bitter).

Related Terms

Whitewash: A paint made from calcium hydroxide and chalk is known as whitewash. It is lime water used as a paint.

Milk of Lime: Calcium hydroxide is sparsely soluble in water. When excess of it is mixed with water, some of its particles remain suspended, imparting the solution a milky appearance. This mixture is known as milk of lime. It has a pH of 12.3

Making Lime Water

The method involves mixing distilled water with calcium hydroxide and shaking the mixture thoroughly, making a saturated solution of calcium hydroxide.

Materials

1 teaspoon of calcium hydroxide (slaked lime)
½ Jar of Water

Steps to Prepare

Pour in 1 teaspoon of slaked lime into a jar filled with water and place a cover on the jar.
Shake it thoroughly. At first, shake for a minute or two and then allow the mixture to stand for 24 hours.
After the given period, pour the solution into another container. Do not stir the sediments vigorously.
The clearer solution must be stored into a clean bottle or jar until its next use.

If excess calcium hydroxide is added, the solution has a milky appearance due to suspended calcium hydroxide particles.

Applications

Calcium hydroxide in lime water reacts with carbon dioxide to give calcium carbonate which forms an insoluble suspension in the solution. This property makes limewater useful in detecting the presence of carbon dioxide. A simple experiment that demonstrates this reaction is to exhale into limewater and observe the change in its color. The carbon dioxide breathed out reacts with calcium hydroxide to form calcium carbonate. And the solution becomes cloudy.
Waste containing sulfur dioxide is treated with limewater to remove the toxic sulfur dioxide from it. Calcium hydroxide in limewater reacts with sulfur dioxide to give calcium sulfite as a precipitate.
Lime water finds applications in cooking. In making tortillas, it is used for soaking maize. In the process, vitamin B and amino acid trytophan are liberated. Soaking in lime water also causes the kernels' skin to peel off.
Lime water is used as a color solvent in fresco painting. Painting is done on wet plaster with the use of pigments dissolved in limewater.
Organisms in reef tanks consume calcium from water. Limewater is added to the tanks to restore the lost calcium.

Limewater is a solution of calcium hydroxide is water. This article tells you how to make it and also gives you some applications of the same

 

 

 

 

Half Life in Nuclear Chemistry

The half-life of radioactive elements is a part of nuclear chemistry. Half-life occurs naturally in some of the radioactive elements while it could be artificially stimulated in some other elements. This article gives a brief introduction to half-life in nuclear chemistry.

Nuclear chemistry is a sub-branch of chemistry. This branch deals with the nuclear processes, radioactivity and nuclear properties. Chemical reactions are the result of the interaction of electrons on the nucleus of an atom while nuclear reactions are different from the traditional chemical reactions and involve the changes in the composition of the nuclei. A nuclear reaction releases enormous amount of energy.

The field of nuclear chemistry was expanded in 1896, when Henri Becquerel discovered that the uranium emitted radiation. Marie Sklodowska Curie turned her focus on studying radioactivity. She propounded the theory that radiation is proportional to the amount of radioactive element present at a give time. She also found out that radiation was a property of an atom. In her lifetime she discovered the two radioactive elements polonium and radium.

In1902, another scientist, Fredrick Soddy, discovered that when a radioactivity occurs; a nuclear reaction changes the nucleus of an atom resulting in the change in the atom. He proposed that all naturally radioactive elements would decay into lighter elements.

Half-Life – Definition

The half-life of a radioactive element is the time required for the element to decay to half of the original amount. For instance, half-life is the time period during which half of the atom of a radioactive element undergoes a nuclear process to be reduced into a lighter element.

Half-Life in Nuclear Chemistry - Half-life Formula

As mentioned above, half-life in Nuclear Chemistry is a decay process of a radioactive element. Each and every radioactive element has its own half-life. For instance, ²³⁸U has a half-life of 4.5billion years. That is, ²³⁸U would take 4.5 billion years to decay into other lighter elements. Another interesting fact is half-life of ¹⁴C is 5730 years and this is very helpful in geological dating of any archaeological material. You must know, the nuclear half-lives of various radioactive elements would range from tiny fractions of a second to many billion years.

You wouldn't be able to predict when a nucleus of a radioactive element would decay but you can calculate how much of the element would decay over a given period of time.

For instance, if you have 5 grams of a radioactive element, after decaying there would be just half the amount of the original i.e. 2.5 grams. After another half-life, the amount of radioactive element left would be 1.25 gram. Here is a formula to calculate half-life of a nuclear element.

A_E = A_o * 0.5^t/t_1/2

Where
A_E = amount of substance left
A_o = original amount of substance
t = elapsed time
t_1/2 = half-life of the substance

Try this problem out as an example. For instance, if you are given 157 grams of ¹⁴C, how much of ¹⁴C would be left after 2000 years. The half-life of ¹⁴C is 5730 years.

A_E = 157 * .5^2000/5730
Amount of ¹⁴C left after 2000 years would be 123 grams.

Three types of natural radioactive decay include alpha radiation, beta radiation and gamma radiation. An alpha radiation is the emission of two protons and two neutrons. An alpha emission is a positive charge and has a helium nucleus. A beta radiation emits more neutrons than protons and has negative charge. In a gamma radiation, the nucleus emits rays in the gamma part of the spectrum. Another interesting fact is a gamma ray has neither mass nor a charge.

While many radioactive elements decay naturally, you can also stimulate a nuclear reaction artificially. The artificially stimulated nuclear reactions are nuclear fusion and nuclear fission.

Ionic Bonding

 

Ionic bonds are characterized by the complete transfer of electrons from one atom to another, resulting in the formation of two charged particles known as ions, which are held together with the help of electrostatic force. Learn more about this intriguing occurrence in chemistry where atoms of different elements combine to form a new substance.
Read more at : http://www.sumichem.blogspot.com

 

Chemistry is fascinating and it is present everywhere around us - be it the beautiful raindrops on your windowpane, sweet sugars in the fruits or the salt that makes your food tastier. Talking about salt, have you ever wondered how sodium and chlorine combine to form the salt (sodium chloride)? Well, it is due a process of bond formation known as ionic bonding.

Basic Concepts in Chemical Bonding
All the chemical compounds are formed due to various combinations of constituent elements. Atoms of the same element or different elements are combined by various chemical bonds in order to keep the molecules together and thus, confer stability to the resulting compounds. Chemical bonds are of various types and possess varied strengths.

1. Valence Electrons and Electronegativity

All the elements possess a certain charge, which is expressed in the number of electrons they carry in the outermost shell or valence shell of their orbit. These electrons are termed as valence electrons and they play a key role in bond formation. The electronegativity of every element depends on the number of valence electrons it carries. Owing to the fact that different elements have different number of valence electrons, they can exhibit different number of valence states.

2. Why are Chemical Bonds Formed?

The purpose behind the formation of chemical bonds of any kind is given by the octet rule, which states that it is the natural tendency of the atoms of elements with lower atomic numbers (less than 20) to attain octet configuration, which is nothing but 8 electrons in the outermost shell. Thus, these atoms are very eager to combine with other elements to attain the configuration of the nearest noble gas. Why? Well, it's simply because noble gas configuration is the most stable.

3. Types of Chemical Bonds

These elements form a bond by donating, accepting or sharing electrons. This is the basic of chemical bonding. The most common types of chemical bonds include:

Covalent bond
Ionic bond
Metallic Bond

While the sharing of electrons by atoms forms covalent bonds, the transfer or electrons from one atom to another form ionic bonds. Here we will discuss in detail the various aspects of ionic bonding.

Understanding the Concept of Ionic Bonding
Ionic bonding is nothing but a type of chemical bond formation that involves complete transfer of electrons from one atom to another. When the atoms lose or gain electrons, they become differentially charged ions or oppositely charged ions. The charged ions are then attracted towards each other due to the electrostatic force, which brings the oppositely charged ions together, resulting in the formation of an ionic bond.

Example

The most common example of ionic bonding is the formation of sodium chloride in which an atom of sodium combines with a chlorine atom.

Let us have a look at the electronic configurations of each.

Sodium (Na) : 2,8,1 and Chlorine (Cl) : 2, 8, 7.

Thus, we see that an atom of chlorine requires only one electron to attain the configuration of the nearest noble gas i.e. Argon (2,8,8). An atom of sodium, on the other hand, requires to get rid of the single electron in its outermost shell to acquire the configuration of the nearest noble gas i.e. Neon (2,8).

In such a scenario, the sodium atom donates its outermost electron to the chlorine atom, which requires only one electron to attain octet configuration. The sodium ion becomes positively charged due to the loss of an electron, whereas the chloride ion becomes negatively charged due to the gain of an additional electron. The oppositely charged ions thus formed, are attracted to each other and result in the formation of an ionic bond.

Characteristics of Ionic Bonds
The presence of ionic bonds affect the chemical and physical properties of the resulting compounds. There exist several prominent characteristics of ionic bonds and here is a list of some of these characteristics:

Owing to the fact that metals tend to lose electrons and non-metals tend to gain electrons, ionic bonding is common between metals and non-metals. Hence, unlike covalent bonds that can only be formed between non-metals, ionic bonds can be formed between metals and non-metals.
While naming the ionic compounds, the name of the metal always comes first and the name of the non-metal comes second. For instance, in case of sodium chloride (NaCl), sodium is the metal whereas chlorine is the non-metal.
Compounds that contain ionic bonds readily dissolve in water as well as several other polar solvents. Ionic bonds, thus, have an effect on the solubility of the resultant compounds.
When ionic compounds are dissolved in a solvent to form a homogeneous solution, the solutions tends to conduct electricity.
Ionic bonding has an effect on the melting point of the compounds as well, as ionic compounds tend to have higher melting points, which means that ionic bonds remain stable for a greater temperature range

 

Molarity Formula
If you are clueless about what is molarity formula or what does molarity mean, you have landed on the right page. Reading this article will clear out all your doubts about what this formula is and how it's used in chemistry applications.

 

If you have recently taken up a lab course in basic chemistry, one of the first things that will bewilder you is molarity and why is it so important in applied chemistry. Going through this Buzzle article will hopefully clear your doubts regarding the concept of molarity (not to be confused with morality, an entirely different concern!).

What is Molarity?

Molarity, also known as molar concentration, is a measure of solute concentration in any solution. That is, it measures how much of a substance is dissolved in any solvent.

Solute is the substance that is mixed in a solvent. For example, consider a mixture of salt mixed in water. Here salt is the solute and water is the solvent and mixed together, they make a solution. To put it bluntly, molarity of salt water will be a measure of how much of salt has been mixed in a unit liter or a measure of salt concentration in water. However 'amount of salt' or solute is still vague. The amount of solute needs to be quantified in the definition of molarity as otherwise it would not be useful. That's why, molarity is defined in the following manner:

"Molarity is a measure of the concentration of a solute in a solution and is quantified as the number of moles of that substance, per unit volume of that solution."

To completely understand what the above definition means, one must know what the chemistry term - 'mole' of a substance is. For those of you who are not familiar with it, let me explain. A mole of a substance is its molecular weight expressed in grams. For example, the molecular weight of Oxygen is 16 and therefore one mole of oxygen is 16 gm. A mole of any substance contains exactly 6.023 x 1023 (Avogadro's Number) molecules. To know the number of moles of any quantity of substance, you must divide the total weight by the weight of one mole.

Moles of a Substance = (Total Mass of the Substance)/(Gram Mole of that Substance)


The unit of molarity is mol/liter.

Standard Formula

Molarity is denoted by the symbol 'M' when talking in quantitative terms and by 'c' when denoting it as a concept. Here are the standard molarity formulas that provide various ways using which you could calculate the molarity of a substance.

Molarity = n / V = N / (NA x V)


where,

n = Number of moles of the substance
V = Volume of the solution (in liters)
N = Number of molecules of substance present in the solution
NA = Avogadro number

So a solution of 1 M or 1 molar concentration has 1 mole of that substance per liter (1 mol/liter). In SI units, molarity may also be measured as 'moles per cubic meter (mol/m3)'. Normally molarity can be measured in 'Moles per decimeter cube (dm3)' as decimeter is a more commensurate unit.

Ergo, to calculate the molarity of a substance one must know the molecular weight of a substance, weight of the substance (from which number of moles can be calculated) and the volume of the solution. Using this formula, solutions of definite concentrations can be created by chemists and they can quantitatively analyze results.

An Example

Problem: Find the molarity of 175.32 gm of Sodium Chloride (NaCl) dissolved in 2 liters of water (Given: Molar Mass of NaCl is 58.44 g/mol).
Solution: Firstly, we must compute the number of NaCl moles.

Moles of NaCl = Total Mass of NaCl/Molar Mass = 175.32/58.44 = 3 Moles

Now we can directly compute the molarity, using the above formula.

Molarity of NaCl = number of Moles (n)/Total Solution Volume (V) = 3 Moles/2 liters = 1.5 mol/liter


Chemistry is a practical science and quantifying the amounts of reactants and products or their concentrations is absolutely important, if experimental results are to make sense. That's why knowing the formula and its use is an essential part of any basic course in chemistry

 

Organic Compounds - Examples
Organic compounds examples are found all around us, as they form the basis of many products that we use today. Read on, to learn more about these compounds, and to see a brief list of the examples.

 

Studying many organic compounds examples has shown us that any chemical compound that contains carbon molecules in its composition is an organic compound. There is even a special branch of chemistry (known as organic chemistry) that is solely dedicated to the study of these. The distinction between organic and inorganic compounds is one that is shrouded with a bit of confusion, as there are some carbonates, allotropes of carbon, and some cyanides that cannot be called organic even though they contain carbon molecules.

Now, an official definition of these compounds does not exist, and this makes the distinction process even harder. Different scientific books often give differing definitions. Some books state that these compounds contain C-H bonds, others state that they contain C-C bonds, and most books say that the simple presence of carbon makes a compound organic in nature.

Despite these differences, the examples remain the same in all these books. Once a compound has become known as an organic, this cannot be altered just like that.

What Are Organic Compounds Made Of

The modern definition and classification of these examples are very different from earlier studies. Today's fairly broad definition that any compound containing carbon qualifies as organic compounds is not completely accurate, as there are several carbon containing alloys that do not figure in this list.

Apart from these alloys (like steel), there are other metal carbonates and carbonyls, simple carbon halides and sulfides and simple oxides of carbon and cyanides as well, that are known as inorganic compounds, even though carbon is a part of their composition. The older definitions (known as 'vitalism') were considered by scientists to originate from living processes, and this led to the name organic compounds. The primary reason for so much ambiguity is that carbon easily combines with many compounds to form molecular chains and rings, and as such there are millions of compounds that contain carbon in them.

Examples

To list out all the organic compounds known to man is a very difficult task, so here you will find the most commonly known and seen examples.

Alkanes

Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Octane
Nonane
Decane

Cycloalkanes

Cyclopropane
Cyclobutane
Cyclopentane
Cyclohexane
Cycloheptane

Here are some more examples for you.

Acid anhydrides
Acyl halides
Alcohols
Aldehydes
Alkenes
Amides
Amines
Aromatics
Azo compounds
Carboxylic acids
Esters
Ethers
Haloalkanes
Imines
Ketones
Nitriles
Nitro compounds
Organometallic compounds
Phenols
Polymers
Thiols
Urea
Valium
Vitamins
Warfarin
Xylene
Xylose
Zingiberene

The wide use and application of organic compounds has made them very useful for the progress and development of mankind. These have a variety of applications in our everyday lives, and it would be impossible to imagine life without them. Apart from forming the basis for many applications and products that we use, these are also the main constituent of all forms of life.

These examples can be classified as natural and synthetic organic compounds, and also on the basis of the many bonds that they are made up of. The study of organic chemistry is very vast and complicated, but ultimately very useful.

Difference Between Organic and Inorganic Chemistry

When taking up your first advanced courses in high school level science, you will find two separate courses named organic and inorganic chemistry listed in the course schedule. Till date, you might have taken up only a single course in basic chemistry and the bifurcation of this subject into two separate parts might baffle you. As a subject advances in its scope of applicability and complexity, it tends to get divided into sub-fields and chemistry is no exception to this. According to the kind of chemical reactions studied and the materials investigated, chemistry is divided into organic and inorganic chemistry. In this Buzzle article, I have elucidated the difference between organic and inorganic chemistry, for beginner students taking up advanced chemistry courses.

What is Organic Chemistry?
Organic chemistry, as the name itself suggests, deals with the study of all kinds of organic compounds. Earlier, the term - 'Organic' addressed compounds of biological origin but now it is broadly defined to apply to all carbon compounds and hydrocarbons (C-H compounds) in particular. These includes alkanes, alkenes, alkynes, aromatic compounds, aliphatic compounds, polymers and biomolecules. It involves the study of structure, properties, synthesis, reactions and applications of organic compounds. Like any other field of chemistry, there is considerable lab work involved in a typical organic chemistry course which focuses on studying characterization, identification and analysis of organic reactions. Advanced courses in organic chemistry study biological reaction mechanisms like cellular respiration, protein synthesis, DNA replication and other such phenomena in substantial detail.

What is Inorganic Chemistry?
Inorganic chemistry focuses on studying the realm of non-organic compounds, which includes all naturally occurring and artificially synthesized metallic and non-metallic compounds. It involves the study of structure, properties and synthesis of these compounds. Advanced inorganic chemistry involves molecular quantum mechanics which provides an accurate description of the molecular structure of inorganic compounds. Reaction mechanisms involving inorganic compounds are studied in detail. Lab work in primary inorganic chemistry courses involves 'Inorganic Qualitative Analysis' aimed at training students in identifying the salts of various types through a series of investigative experiments. It also involves several quantitative analysis methods, like titration and actual synthesis of inorganic compounds.

How is Organic Chemistry Different From Inorganic Chemistry?
After having defined the subject scope details of both chemistry branches, the differences between them should be already clear. While organic chemistry studies hydrocarbon compounds or organic compound complexes in general, inorganic chemistry studies the rest of subset of compounds, other than organic compounds. This clear distinction was necessary due to the higher complexity of organic compounds compared to inorganic compounds.

This necessitates a different set of analytical tools and ideas, for studying both subjects, which justifies the bifurcation. The scope of organic chemistry is much more wider than inorganic chemistry as it naturally prepares a student for higher studies in biotechnology, genetic engineering, microbiology, biophysics and other advanced biological sciences. Theoretical inorganic chemistry is in fact quantum physics and people with an analytical bend of mind, with a love for physics and mathematics, will find it to be an exciting field. Both are sufficiently interesting subjects of study. If you plan to make a career in biotechnology, a grounding in organic chemistry is a must. Inorganic chemistry provides access to the highly interesting field of nanotechnology. I suggest that you take up both courses, if you plan to make a career as a chemist as both train you to understand the structure of matter in a range of different material manifestations.

Thus the prime difference between organic and inorganic chemistry lies in the subjects of study. While one is primarily devoted to the study of carbon compounds including hydrocarbons, the other focuses on the study of the entire gamut of non-organic reactions. In organic chemistry, you will spend a considerable amount of time in rightly naming various types of organic compounds according to the right nomenclatures and then study the various synthesis methods of each different type of organic compound. This is just basic preparation.

Real organic chemistry starts when you start understanding the underlying mechanisms that make organic reactions possible and apply the knowledge in understanding various biological reactions. Inorganic chemistry will first focus on defining and describing various types of inorganic compounds, their structure and reactions. The division of a field into sub-parts is only for our own convenience. There are several phenomena where both inorganic and organic chemistry principles must overlap to provide us with some real answers. One such field where both fields merge is 'Organometallic Chemistry'. Hope this differentiation of organic and inorganic chemistry was an insightful read for you.

Chemistry in Everyday Life

Chemistry, though a mystery to many, is heavily involved in every aspect of our daily life. Our very existence depends upon it. By reading the examples below you will realize how vital chemistry is in everyday life

Did you know...

... that the human body contains enough carbon to provide 'lead' (which is really graphite) for about 9,000 pencils.

Chemistry is a branch of science which deals with the study of the composition, structure, properties, reactions and behavior of substances. Hence, chemistry is termed as the central science. It is the essence of our everyday lives and occurs in the food we eat, the air we breathe, the water we drink, everything is a result of chemical processes.

In fact, emotions like love, hatred, are also driven by chemistry. For a better understanding of the chemistry that is virtually everywhere around us, we have provided day-to-day examples in two sections. Firstly, examples of chemistry within our body and secondly, examples of chemistry that exist outside our body or occur around us.

Chemistry Within Us

Chemistry plays a vital role in our survival, and life without chemicals can't even be imagined. They participate in the primary functions of the body, control our emotions, oversee the metabolic processes and keep diseases at bay. The oxygen that we breathe, the essential nutrients that we require, the genetic make-up of our body - the DNA and RNA - are all made up of different elements and compounds. Let us take a look at few such instances that involve chemistry, and are an integral part of our existence.

1. Composition of the Human Body

Roughly 96% of our body mass is made up of just 4 elements:- Oxygen, Carbon, Hydrogen and Nitrogen. The remaining 3% consists of around 60 elements that include sodium, potassium, calcium, zinc etc., and the list goes on. The elements that are required in larger amounts are called macro-nutrients and the others that are needed in minute quantities, usually in parts per million or less, are called micro-nutrients. Chemically, the human body is made up of water and organic compounds- carbohydrates, proteins, lipids and nucleic acids.

2. Metabolism

The organic processes taking place in the human body are termed as metabolism, which involves huge number of chemical reactions. The enzymes that are secreted by different organs act as biocatalysts that speed up the rate of these reactions, whereas the hormones regulate their occurrence, time and speed. Our well-being, smooth functioning and normal health depends on these metabolic processes. The coordination and simultaneous occurrences of these life processes in an orderly manner is the reason we are fit, healthy and alive.

3. Respiration

Breathing is the exchange of gases between an organism and its environment. Respiration is a chemical process, which is a reaction between glucose or sugars with oxygen, that release energy. It is the process in which inhalation of oxygen from the air causes inflation of the lungs and then deflation occurs by exhaling carbon dioxide into the environment. The reaction that takes place during breathing is :-
C6H12O6 + 6O2 ➜ 6CO2 + 6H2O + Energy

4. Composition of Water

Water is the elixir of life on Earth. Hydrogen - a highly-combustible gas and Oxygen - a gas without which combustion is impossible, form a covalent bond with each other to create the most effective fire extinguisher which is water. The chemical formula of water is H2O. Yes! We drink a chemical everyday. Water is important for all the metabolic processes that occur inside our body. As Leonardo da Vinci stated "Water is the driving force of all nature."

5. Feeling Hungry

When you feel hungry the hormone ghrelin is secreted by the stomach that triggers hunger. It stimulates the release of the growth hormone. It plays a role in the release of insulin and protection of the cardiovascular organs. So, the next time your stomach growls grab a bite because if you fast or skip meals, more ghrelin is produced thus increasing your craving for food.

6. Digestion

Gastric acid is composed of hydrochloric acid (HCl) and large quantities of potassium chloride(KCl) and sodium chloride(NaCl) that is secreted by the parietal cells lining the stomach. This gastric acid helps convert pepsinogen to pepsin which is responsible for the denaturing of the proteins in the stomach. It also kills the micro-organisms in the food before they can make you sick. The HCl neutralizes the acid present in the foods you eat thereby maintaining your body's acidic or alkaline levels to keep you healthy.

7. Tears and Crying

Sometimes, crying is a natural reflex. Studies have shown that emotional tears contain more manganese, an element that affects temperament and more prolactin. Prolactin is a hormone that regulates milk production. This elimination of manganese and prolactin is thought to ease out tension building up in the body and you feel energized and rejuvenated. So, the next time you feel low and need to vent your emotions, don't hold back. Just cry! It will help you feel better.

8. Chemistry of LOVE

You fall in love or are attracted to someone and have a feeling of belonging due to an increase in the secretion of -Phenylethylamine (PEA, or the "love chemical") and the hormones testosterone and estrogen which promote mating. When we fall in love, our brain releases dopamine, norepinephrine and pheromones consistently, which evoke the pleasure center in the brain leading to side effects such as increased heart rate, insomnia, an intense feeling of excitement, elation and focused attention.

9. Coffee and Sleep

Coffee keeps you awake due to the presence of caffeine in it. This caffeine increases dopamine levels in our bodies that stimulates the 'pleasure areas' in our brain making us feel good. It increases the adrenaline secretion in the body and speeds up activity in the brain that keeps us awake.

10. Body Odor

Perspiration is a way in which the body cools itself. Body odor mainly originates from the apocrine glands which are found in the armpits, ears, breasts, the genitals and hair follicles that become active at the onset of puberty. The sweat that these glands release is slight yellow in color due to the presence of fatty acids and proteins in it. The bacteria that thrive on our skin break down the secretions of the apocrine glands and create smelly odors.

These are some of the examples of chemistry inside our body. Let's look at some examples of chemistry in day-to-day life that take place around us.

Chemistry Around Us

Chemical reactions influence the stuff around us and there are numerous instances where chemicals and chemistry helps us live a better life. The cooking of food, the clothes we wear, fertilizers that we use for crops, cement used for building our houses, the power plants that generate electricity, and many other processes depend on chemistry. The human dependence on this natural science is increasing and to understand this, here are a few examples that highlight the importance of chemistry around us.

1. Photosynthesis

Photosynthesis involves energy transformation and is a chemical process wherein plants, algae and some bacteria produce their own food. It is the synthesis of glucose using carbon dioxide and water in presence of sunlight trapped by chlorophyll present in the leaves. The reaction which occurs is depicted as:
6 CO2 + 6 H2O + Light Energy ➜ C6H12O6 + 6 O2

Photosynthesis is the reverse process of respiration. They both are inter-dependent. We get an uninterrupted supply of oxygen, and plants get the carbon dioxide they need. Thus, photosynthesis plays a significant role in our day-to-day life.

2. Color of Meat

There are two types of meat: red and white. Red meat contains a highly pigmented protein called myoglobin that stores oxygen in the muscle cells. More the myoglobin in the cells, the redder is the meat. However, as meat is heated, the proteins break down and shrink in size. When the interior of the meat reaches 170° F, hemichrome (a tan colored compound) levels rise, and the myoglobin becomes metmyoglobin, which gives well-done meat its brown-gray shade. White meat contains glycogen, which has a translucent "glassy" quality when it is raw. When it's cooked, the proteins recombine, or coagulate, and the meat becomes opaque and whitish.

3. Apples Turning Brown

Apples contain an enzyme called polyphenol oxidase (PPO), also known as tyrosinase. Cutting an apple exposes its cells to the atmospheric oxygen and oxidizes the phenolic compounds present in apples. This is called the enzymatic browning that turns a cut apple brown. In addition to apples, enzymatic browning is also evident in bananas, pears, avocados and even potatoes.

4. Crying and Onions

When you cut an onion you break the cells that form the layers in an onion, thus releasing an enzyme alliinase that reacts with a sulfur-containing compound known as 'prensco', which is also released while cutting. This reaction results in the formation of 1-propenyl sulfenic acid. This acid is further converted to Propanethiol S-oxide, a volatile sulfur compound, by the enzyme LF-synthase (meaning Lachrymatory Factor synthesizing enzyme). This gas, known as the Lachrymatory factor (crying factor), reacts with the water in our eyes to form sulfuric acid causing a burning sensation in your eyes and indicating the tear gland to secrete tears.

5. Stain Removers

Soap is formed by the reaction between an alkali and a fatty acid. This produces a molecule with one hydrophilic (water-loving) and one lipophilic (fat-loving) ends. The lipophilic ends stick to oil, grease or dirt. These get engulfed in the soap and are washed away with a fresh stream of water, leaving a clean surface behind. This is just a physical reaction that takes place. Soap and stain removers act as emulsifiers which allow oil and water to mix and so the oily mixtures and difficult stains on body and clothes can be removed after application of soap, stain removers and water.

6. Ripening of Fruits

A simple hydrocarbon gas ethylene switches on the necessary genes that stimulate the secretion of the ripening enzymes which catalyze reactions to change the properties of the fruit. Ethylene channelizes the action of several other chemicals called hydrolase, amylase, kinase and pectinase. These enzymes convert starch to sugar, alter the cell walls to make them softer, neutralize acids and cause the fruit to emit an aroma.

7. Fermentation

Fermentation is the conversion of complex substances to simpler ones under anaerobic conditions. The specific product from fermentation is driven by the type of micro-organisms acting on the substance in which the fermentation occurs. The products of fermentation are alcohols or acids and the release of carbon dioxide. For example, wine produced from fruit juice is an alcohol as a result of fermentation by yeast, whereas beer is the result of yeast fermentation of grain. Antibiotics are obtained through fermentation by molds and some bacteria. Yogurt, cheese and vinegar are products of bacterial fermentation. Leavened bread is obtained by yeast fermentation.

8. Sunscreens

Sunscreens are a combination of organic and inorganic compounds. Inorganic chemicals like titanium dioxide or zinc oxide, form a physical barrier that reflects or scatters UV waves. Organic components like octyl methoxycinnamate (OMC) or oxybenzone absorb UV rays and release their energy as heat. This protects our skin from sunburns and detrimental effects like cancer.

9. Nail Paint Removers

Nail paint consists of three types of ingredients which are organic solvents and drying agents, thickeners and hardening agents along with coloring agents. The remover is actually an organic solvent that is used as an ingredient in nail paint which may be acetone or ethyl acetate. So when you apply the remover you are just bringing it back to its original state. The solvent molecules get in between the chains of polymers and separate them, making it easy to wipe it off with a ball of cotton.

10. Static Shocks

All materials are made up of electrical charges in the atoms of the material. There are equal quantities of electrons (negative charges) and protons (positive charges) that try to balance each other in the universe. Friction between two materials causes these charges to redistribute. The electrons from one atom are transferred to the other. As we know, like charges repel each other and unlike charges attract each other. Whenever you touch anything that is a good conductor of electricity, the transfer of the extra electrons that have accumulated takes place, and it gives you the static shock. For example, generally in winters, you get a shock when you get out of the car or when you touch the door knob or filing cabinet.

Your body itself is a huge chemical factory wherein one or the other chemical reaction takes place every moment. Most people detest chemistry because of long reactions and difficult chemical names that we see in our books. However, taking a practical approach to understanding this science, that we come across in our everyday life