Question

Which among the following salts forms basic solution in water?

• A. \(\mathrm{NH}_{4}\mathrm{NO}_{3}\)
• B. \(\mathrm{NH}_{4}\mathrm{Cl}\)
• C. \(\mathrm{Na}_{2}\mathrm{CO}_{3}\)
• D. \(\mathrm{Na}_{2}\mathrm{SO}_{4}\)

Hint:

A salt of a strong base and a weak acid hydrolyses to give a basic solution.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
The nature of a salt solution depends on the strengths of the parent acid and base.

Step 2: Check the Options
\(\text{NH}_4\text{NO}_3\) and \(\text{NH}_4\text{Cl}\) come from a weak base and strong acids, so they are acidic.
\(\text{Na}_2\text{SO}_4\) comes from a strong base and strong acid, so it is neutral.

Step 3: Basic Salt
\(\text{Na}_2\text{CO}_3\) comes from \(\text{NaOH}\) (strong base) and \(\text{H}_2\text{CO}_3\) (weak acid).
\(\text{CO}_3^{2-} + \text{H}_2\text{O} \rightleftharpoons \text{HCO}_3^{-} + \text{OH}^{-}\)
The \(\text{OH}^{-}\) ions make the solution basic.

Final Answer:
Sodium carbonate forms a basic solution. \[ \boxed{\text{(C) }\text{Na}_2\text{CO}_3} \]