Question

The reactions favoured by light are called:

• A. endothermic reactions
• B. exothermic reactions
• C. photochemical reactions
• D. none of the above

Answer 1

The correct option is C photochemical reactions

Photochemical reactions are the reaction that takes place in the presence of light.

For example, photosynthesis of plants. Photographic films which are coated with silver bromide (very small amount of silver iodide) undergo a chemical reaction when exposed to sunlight.

$C{H}_4\left(g\right)+C{l}_2\left(g\right)\to C{H}_{3}Cl\left(g\right)+Hcl\left(g\right)$

$6C{O}_2\left(g\right)+6H_{2}O\left(l\right)\to C_6{H}_{12}{O}_6\left(aq\right)+6O_2\left(g\right)$

$2AgBr\left(s\right)\to 2Ag\left(s\right)+B{r}_2\left(l\right)$

Thus option $C$ is correct.