Question

The use of common salts, e.g., $NaCl$ or $CaC{l}_2$ anhydrous is made to clear snow on the roads. This causes :

• A. a lowering in f.pt. of water
• B. a lowering in m.pt. of ice
• C. ice melts at the temperature of atmosphere present at that time
• D. all of the above

Answer 1

Answer: (D)

all of the above

Option (D) is correct.
Addition of salt lowers the freezing point of water and thus, snow melt.
Mixing common rock salt with some of the organic compounds and magnesium chloride results in spreadable materials that are both effective to much colder temperatures (${30}^{o}F/{34}^{o}C$) as well as at lower overall rates of spreading per unit area.