Question

Which of the following is a basic salt?
(A) $SnC{l_2}$
(B) NaCl
(C) $N{H_4}Cl$
(D) $C{H_3}COONa$

Answer 1

Hint: Any salt that hydrolyses to form a basic solution is a basic salt. Chloride ions being weakly acidic do not get hydrolysed and in its place they exchange ions.


Complete answer:
-Basic salts are formed as a result of incomplete neutralisation of strong base and weak acid. They are basic or alkali in nature. The conjugate base formed from the weak acid can hydrolyse and form a basic solution which makes it a basic salt.

In short we can also say that if a salt can deprotonate water and yield a basic solution it is known as a basic salt.
Example: Calcium carbonate, Sodium hydroxide, etc.
-Such salts are insoluble and formed by precipitation reactions.
-The chloride ions present in any compound can be oxidised but they cannot be reduced. The chloride ions have a negative value of pKa which shows that they are very weak bases in terms of acid-base properties. The ionic chloride salts can react with other salts and exchange anions in the process. But they do not hydrolyse in any forms to produce a basic solution.
Hence salts containing chloride ions ($C{l^ - }$) or chloride salts cannot be basic salts and so $SnC{l_2}$, NaCl and $N{H_4}Cl$ are not basic salts.
-Sodium acetate ($C{H_3}COONa$) is the sodium salt of acetic acid ($C{H_3}COOH$) which is a weak acid. Also a solution of acetic acid and sodium acetate acts as a buffer and keeps the pH constant. This solution is known as vinegar.
So, sodium acetate ($C{H_3}COONa$) is a basic salt.

So, the correct answer is “Option D”.

Note: If there is complete neutralisation of any acid and base then the salt formed won’t be a basic salt. For a salt to be basic there has to be incomplete neutralisation of any strong base and a weak acid so that the salt has more basic properties.