Question

Name the compounds obtained on heating baking soda.

Answer 1

Baking soda

• Sodium bicarbonate (${\mathrm{NaHCO}}_3$) is also commonly known as baking soda.
• It comprises of a sodium cation $\left({\mathrm{Na}}^{+}\right)$and a bicarbonate anion$\left({{\mathrm{HCO}}_3}^{-}\right).$
• It is an amphoteric compound.
• Its aqueous solutions are mildly basic due to the formation of carbonic acid and hydroxide ion:

$\underset{\mathrm{Carbonate}\mathrm{ion}}{{{\mathrm{HCO}}_3}^{-}}+\underset{\mathrm{water}}{{\mathrm{H}}_2\mathrm{O}}\to \underset{\mathrm{Carbonic}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{CO}}_3}+\underset{\mathrm{hydroxide}\mathrm{ion}}{{\mathrm{OH}}^{-}}$

Baking soda on heating

• On heating baking soda above${60}^{\mathrm{o}}\mathrm{C}$, baking soda gradually decomposes into sodium carbonate, water and carbon dioxide.
• Reaction:

$2{\mathrm{NaHCO}}_3\left(\mathrm{s}\right)\to \underset{\mathrm{Sodium}\mathrm{carbonate}}{{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

On heating, baking soda decomposes into sodium carbonate, water and carbon dioxide.