Which of the following salts will give highest `pH` in water?

Options

A. `KCl`
B. `NaCl`
C. `Na_(2)CO_(3)`
D. `CuSO_(4)`

Answer

C

Explanation

The highest pH refers to the basic solution containing `OH^(-)` ions. Therefore, the basic salt releasing more `OH^(-)` ions on hydrolysis will give highest pH in water. Only the salt of strong base and weak acid would release more `OH^(-)` ion on hydrolysis. Among the given salts, `Na_(2)CO_(3)` corresponds to the basic salt as it is formed by the neutralisation of NaOH [strong base] and `H_(2)CO_(3)` [weak acid]. `CO_(3)^(2-)+H_(2)O hArr HCO_(3)^(-)+OH^(-)`