Question

Define:

(a) Photochemical reaction

(b) Electrochemical reaction.

Give one example in each case.

Answer 1

(a) It is a reaction which occurs with the absorption of light energy
Example: Photosynthesis

$6C{0}_2$ + $H_{2}O$ $\to$ $C_6{H}_{1}2O_6$ + $6O_2$

(b) It is a reaction which occurs with the absorption of electrical energy
Example: Acidulated water breaks into hydrogen and oxygen.

$2H_{2}O$ $\to$ $2H_2$ + $O_2$