Question

How many photons of light having frequency 0.53 Hz are required to break a $C-O$ bond, if the bond energy of $C-O$ bond is 350 kJ/mol?

• A. $1.66\times {10}^{15}$
• B. $2.52\times {10}^{15}$
• C. $3.08\times {10}^{15}$
• D. $4.12\times {10}^{15}$

Answer 1

The correct option is A $1.66\times {10}^{15}$

Given,
The frequency of light ($\nu$) = 0.53 Hz
So, from Planck's quantum theory,
energy of a photon $E=h\nu =6.62\times {10}^{-34}\times 0.53J\approx 3.50\times {10}^{-34}J$

Again, $\text{Bond energy of}C-Obond=350kJ/mol$
So, number of photons required to break one $C-O$ bond
$=\frac{350\times {10}^3}{(6.022\times {10}^{23})(3.50\times {10}^{-34})}=1.66\times {10}^{15}$