UPSC CDS II 2024 GK Paper

Concept:Potassium nitrate ($\mathrm{KNO}_3$) is used in fertilizers, medicine, and gunpowder, but not as a meat preservative.Explanation:Potassium nitrate is a key component in fertilizers, providing nitrogen and potassium for plant growth.It has medical uses, such as reducing tooth sensitivity in toothpaste and as a diuretic.It is an oxidizer in gunpowder, mixed with charcoal and sulfur.However, for preserving meat products, sodium nitrate ($\mathrm{NaNO}_3$) or sodium nitrite ($\mathrm{NaNO}_2$) are preferred.These sodium compounds inhibit bacterial growth (e.g., Clostridium botulinum) and maintain meat colour better than potassium nitrate.Thus, potassium nitrate is not used as a preservative for meat.Answer:As a preservative of meat products (Option D).