Question

Given below are two statements ; one is labelled as Assertion A and the other is labelled as Reason R

Assertion (A): The aqueous solution of \(CH_3COONa\) is alkaline in nature.

Reason (R): Acetate ion undergoes anionic hydrolysis 

In the light of the above statements, choose the correct answer from the options given below

• A. both (A) and (R) are true and (R) is the correct explanation of (A).
• B. both (A) and (R) are true but (R) is not the correct explanation of (A).
• C. (A) is true but (R) is not true.
• D. (A) is not true but (R) is true.

Answer 1

The Correct Option is A

$CH _{3} COONa + H _{2} O \rightarrow CH _{3} COOH + NaOH$
The above process takes place in following steps
$CH _{3} COONa$ lonisation $CH _{3} COO ^{-}+ Na ^{+}$in aqueous solution strong base
$CH _{3} COO ^{-}+ H _{2} O \rightarrow CH _{3} COOH + OH ^{-}$
Acetate ion undergoes hydrolysis and the resulting solution is slightly basic due to excess of $O H^{-}$ions.

Answer 2

In order to answer the question, first we must know the meaning of hydrolysis. Hydrolysis of an ionic compound is the dissolution of the ions of that ionic compound in water, so the bonds in the compound break and a new compound formation begins. To determine whether the hydrolysis is cationic or anionic we must have to check the ion undergoing hydrolysis.

Complete step-by-step answer:

Sodium acetate \(CH_3COONa\) is a salt of acetic acid that is formed by the reaction of sodium hydroxide and acetic acid. The formation of sodium acetate salt is shown as follows:
\(CH_3COOH + NaOH→CH_3COONa + H_2O\)
Sodium acetate is an ionic compound, so, on hydrolysis first, it goes through an ionization process. The ionization of sodium acetate is shown as follows:
\(CH_3COONa→CH_3COO^− + Na^+\) (Na⁺is spectator cation)
By the ionization sodium ion and acetate ion form. The sodium ion is a spectator ion because it just balances the charge of the acetate ion.
So, the acetate ion undergoes a dissolution process which is shown as follows:
\(CH_3COO^−+H_2O→CH_3COOH + OH^−\)
By the dissolution of acetate ion, acetic acid, and hydroxide ion form. As the acetate ion is an anion so, this is termed anionic hydrolysis. The solution is not neutral but slightly alkaline due to the presence of hydroxide ions in the solution.
So, assertion (A), the aqueous solution of \(CH_3COONa\) is alkaline in nature and the reason (R) is, an acetate ion that undergoes anionic hydrolysis, both are true.
The solution is alkaline due to the hydrolysis of acetate ions. So, the reason explains the assertion.
The correct option is (A), Both A and R true, R is the correct explanation of A.

Note: During hydrolysis two processes take place, first ionization (formation of ions) and second dissolution (reaction of ions with water). Salts are composed of ions. Anionic hydrolysis gives the alkaline solution whereas Cationic hydrolysis gives the acidic solution. An aqueous solution is one in which liquid water is the solvent and the solute ions are surrounded by water molecules and incorporated into the network of bonds within the water. Acetic acid is a weak acid. The anion of acetic acid is known as an acetate ion.

Answer 3

The Correct option is (A)

\(CH_3​COONa+H_2​O→CH_3​COOH+NaOH\)
The above process takes place as mentioned in the following steps:

\(CH_3​COO^−+H_2​O→CH_3​COOH+OH^−\)
Acetate ion undergoes a hydrolysis process and the resulting solution is slightly basic due to an excess of OH⁻ ions.