The energy required to break one mole of CI - Cl bonds in `Cl_(2)," is "242" kJ mol"^(-1)`. The longest wavelength of lig capable of breaking Cl-Cl bonds is `(c = 3 xx 10^(8)" ms"^(-1) and N_(A) = 6.02 xx 10^(23)" mol"^(-1))`

Options

A. 494 nm
B. 594 nm
C. 640 nm
D. 700 nm

Answer

A

Explanation

Energy required to break `Cl_(2)` molecule `=(242xx10^(3)) N_(A) J`
From `E = hv rArr E=h (c )/(lamda)" We have "lamda =(6.626xx10^(-34)xx3xx10^(8)xx6.022xx10^(23))/(242xx10^(3))=494.7 nm`