Question

By giving a reason state why chemical change takes place in the following case: Baking of cake.

Answer 1

• Chemical change: The process in which the composition of the substance is completely altered and a new product is formed is called a chemical change.
• Generally, chemical changes are irreversible i.e., once a chemical change occurs and a new substance is formed, the original substance cannot be obtained back from it.
• Baking of cake is a chemical change as it involves the use of baking soda or Sodium bicarbonate $\left({\mathrm{NaHCO}}_3\right)$ which on heating produces Sodium Carbonate $\left({\mathrm{Na}}_2{\mathrm{CO}}_3\right)$, water $\left({\mathrm{H}}_2\mathrm{O}\right)$ and carbon dioxide $\left({\mathrm{CO}}_2\right)$ gas due to which it becomes light and fluffy.

$2{\mathrm{NaHCO}}_3\left(\mathrm{s}\right)\stackrel{\mathrm{Heat}}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$