JKSSB Sub Inspector of Police (JKPSI) 2022 — Q56 Solved Answer with Explanation

Question

Which one of the following substances is usually used in cold countries to melt ice accumulated on the roads during winter?

1. A. Salt (Correct answer)
2. B. Urea
3. C. Boric Acid
4. D. Hydrogen Peroxide

Correct Answer

Option A — Salt

Detailed Solution & Explanation

Salt is used in cold countries to melt ice on roads because it lowers the freezing point of water -- a phenomenon called freezing point depression. When salt (NaCl) dissolves in water, it dissociates into ions that disrupt the formation of ice crystals, requiring a lower temperature to freeze. This means ice on roads melts at temperatures below 0 degrees C. Road salt (typically rock salt or calcium chloride) can prevent ice formation and make roads safer during winter.