the heat of atomization of methane and ethane are 360 KJ/mol and 620 KJ/mol , respectively . The longest Wavelength of light capable of breaking . The c-c bond is :
(Avogadro number`=6.02xx10^(23),h=6.62xx10^(-34)Js)`

Options

A. `2.48 xx 10^(-3)` nm
B. `1.49 xx 10^(3)` nm
C. `2.49 xx 10^(4)` nm
D. `2.48 xx 10^(4)` nm

Answer

B

Explanation

`CH_(4)(g)rarr C(g) + 4H(g)`
`implies " " 4xx E_(C-H) = 360 KJ//Mol." " implies E_(C-H)=90KJ//Mol.`
and `C_(2)H_(6)(g) rarr 2C(g) + 6H(g)`
`E_(C-C)+ 6 xx90 = 920 " " implies" " E_(C-C)=80 KJ//mol`
` implies N_(A) xx (hc)/(lambda) = 80 xx 1000 J`
`lambda =(6.02 xx 10^(23) xx 6.62xx 10^(-34) xx 3 xx 10^(8))/(80000) = 14.9 xx 10^(-7)m = 1.49 xx 10^(-6)m =1.49 xx 10^(3)` nm