Question

Match the following process with their types.

• A. Endothermic
• B. Exothermic
• C. Photochemical

Answer 1

During melting the ice absorbs heat to change its state from solid to liquid. Hence, it is an endothermic process.

During formation of ice the water loses heat and changes its state from liquid to solid. In other words, the formation of ice involves liberation of heat. Therefore, it is an exothermic process.

Photosynthesis is the process in which carbon dioxide ${\text{(CO}}_2)$, water ${\text{(H}}_2\text{O)}$ reacts in the presence of sunlight to form carbohydrate (glucose) ${\text{(C}}_6{\text{H}}_{12}{\text{O}}_6)$ and oxygen ${\text{(O}}_2)$. The reaction involved is:
${\text{6CO}}_2{\text{(g) + 6H}}_2\text{O(l)}\stackrel{\text{Sunlight}}{\to }{\text{C}}_6{\text{H}}_{12}{\text{O}}_6{\text{(s) + 6O}}_2\text{(g)}$

Since photosynthesis is initiated by light, it is a photochemical process.