Question

The bonds of oxygen molecules are broken by sunlight. The minimum energy required to break the oxygen-oxygen bond is 495 kJ/mol O2. What wavelength of sunlight is required to break the bond in one O2 molecule?

Answer 1

Answer:

The wavelength of sunlight is required to break the bond in one oxygen molecule is 242 nm.

Explanation:

Energy required to break the 1 mol oxygen-oxygen bond:

=495 kJ=495000J

1 mol = $6.022\times 10^{23}$ molecules

Energy required to break 1 molecule of oxygen molecule= E

= $E=\frac{495000 J}{6.022\times 10^{23}}=8.219\times 10^{-19} J$

The energy required to break the  1 molecule of oxygen is equal to enrgy of one photon of a sunlight.

$E=\frac{h\times c}{\lambda}$

where,

$\lambda$ = wavelength of the light

E = energy of the photon

h = Planck's constant = $6.63\times 10^{-34}Js$

c = speed of light = $3\times 10^8m/s$

$\lambda=\frac{h\times c}{E}$

$\lambda =\frac{6.63\times 10^{-34}Js \times 3\times 10^8m/s}{8.219\times 10^{-19} J}=2.42\times 10^{-7} m=242 nm$

The wavelength of sunlight is required to break the bond in one oxygen molecule is 242 nm.