Question

Classify the following reaction into exothermic and endothermic reactions-

Photosynthesis

Answer 1

1. Exothermic reactions: The reactions in which heat is evolved are called exothermic reactions.
2. Endothermic reactions: The reactions in which heat is absorbed during a reaction are called endothermic reactions.
3. Photosynthesis: During photosynthesis, the carbon dioxide (${\mathrm{CO}}_2$) and water (${\mathrm{H}}_2\mathrm{O}$) in plant absorb heat energy from the sun and produces glucose (${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$) and oxygen (${\mathrm{O}}_2$).

$$\begin{gathered} 6{\mathrm{CO}}_2\left(\mathrm{g}\right)+6{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)+\mathbf{}\mathbf{Heat}\mathbf{}\to {\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\left(\mathrm{s}\right)+6{\mathrm{O}}_2\left(\mathrm{g}\right) \\ \mathrm{Carbon}\mathrm{water}\mathrm{Glucose}\mathrm{Oxygen} \\ \mathrm{dioxide} \end{gathered}$$

4. Heat is absorbed here. Hence, photosynthesis is an endothermic reaction.