In: Chemistry
The fundamental vibrational frequencies for 1H2and 14N2 are 4401 and 2359 cm−1, respectively, and De for this molecules is 7.677×10−19 and 1.593×10−18 J respectively. |
Part A Using this information, calculate the bond energy of 1H2. Express your answer to four significant figures and include the appropriate units.
SubmitMy AnswersGive Up Part B Calculate the bond energy of 14N2. Express your answer to four significant figures and include the appropriate units.
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The expression for Energy, En=hν(n+1/2)- [(hν)2(n+1/2)2]/4De
For, fundamental vibration, n=0
Therefore, E0=hν/2- (hν)2/16De
Where, h=Planck’s constant =6.626x10-34Js
and ν=fundamental frequency
Bond Energy =D0= De-E0
Part A: For H2: 1/λ=4401cm-1 ; De=7.677x10-19J
ν=c/ λ=1.32x1014s-1
E0= (6.626x10-34) (1.32x1014) /2- [(6.626x10-34) (1.32x1014)]2/16(7.677x10-19)
E0= 4.3108x10-20J
Therefore, Bond Energy =D0= De-E0 =7.677x10-19 - 4.3108x10-20 J =7.246 x10-19 J
Part B: For N2: 1/λ=2359cm-1 ; De=1.593 x10-18J
ν=c/ λ=7.07x1013s-1
E0= (6.626x10-34) (7.07x1013) /2- [(6.626x10-34) (7.07x1013)]2/16(1.593x10-18)
E0= 2.333x10-20J
Therefore, Bond Energy =D0= De-E0 =1.593 x10-18 - 2.333x10-20 J =1.569 x10-18 J