Question

A small amount of baking soda can act as a preservative for milk since it

• A. kills undesirable bacterias present in milk
• B. imparts good taste to milk
• C. removes alkalies if any present in the milk
• D. neutralizes lactic acid in milk

Answer 1

The correct option is D

neutralizes lactic acid in milk

Explanation for the correct option:

(D) neutralizes lactic acid in milk

1. Lactic acid$\left({\mathrm{C}}_3{\mathrm{H}}_6{\mathrm{O}}_3\right)$ is found in milk.
2. Baking soda or sodium bicarbonate$\left({\mathrm{NaHCO}}_3\right)$ is a basic salt.
3. The baking soda acts as a preservative when added to milk because it neutralizes the lactic acid present in milk.
4. Due to this, the microbial growth stops, and milk gets preserved.

Explanation for the incorrect options:

(A) kills undesirable bacterias present in milk

1. The baking soda does not kill the undesirable bacteria in milk.
2. It instead stops the growth of bacteria.

(B) imparts good taste to milk

Baking soda does not impart a good taste to milk.

(C) removes alkalies if any are present in the milk

Baking soda itself being a base cannot remove alkalies present in milk.

Hence, the correct option is (D).