Question

Sodium salt of acid present in vinegar is an example of :

• A. Salt of strong acid + strong base
• B. Salt of weak acid + strong base
• C. Salt of strong acid + weak base
• D. Salt of weak acid + weak base

Hint:

To find the parent acid and base of any salt:
- Add \(OH^-\) to the cation (e.g., \(Na^+ + OH^- \to NaOH\), a strong base).
- Add \(H^+\) to the anion (e.g., \(CH_3COO^- + H^+ \to CH_3COOH\), a weak acid).
This simple method helps classify any salt.

Answer 1

The Correct Option is B

Step 1: Identify the acid in vinegar.
Vinegar's sour taste comes from acetic acid, $CH_3COOH$. This is a carbon based acid that does not break apart completely in water, so we call it a weak acid.
Step 2: Identify the base used to make its sodium salt.
To convert an acid into its sodium salt, we always react it with a sodium base, here sodium hydroxide, $NaOH$. $NaOH$ dissolves completely in water and ionises fully, so it counts as a strong base. \[ CH_3COOH + NaOH \to CH_3COONa + H_2O \]
Step 3: Combine the two strengths.
One partner is weak, the acid, the other is strong, the base, so the resulting salt, sodium acetate, falls in the weak acid plus strong base category. A quick check, a solution of this salt turns slightly basic, pH above 7, on hydrolysis, which is the signature behaviour of this exact salt type.
Step 4: Conclude.
Sodium acetate, the sodium salt of vinegar's acid, is a salt of weak acid and strong base. \[ \boxed{\text{Salt of weak acid + strong base}} \]