Question

The aqueous solution of sodium carbonate is alkaline. Why?

Hint:

Sodium carbonate is used in laundry detergents due to its alkalinity.

Answer 1

Sodium carbonate (\( Na_2CO_3 \)) is a salt of a strong base (NaOH) and a weak acid (H\(_2\)CO\(_3\)). When dissolved in water, it undergoes hydrolysis:
\[ Na_2CO_3 + H_2O \rightarrow 2Na^+ + HCO_3^- + OH^- \] Since hydroxide (\( OH^- \)) ions are produced, the solution becomes alkaline.