For the Assertion (A) and Reason (R) below, choose the correct alternative:
Assertion (A) : When common salt is kept open, it absorbs moisture from the air.
Reason (R) : Common salt contains magnesium chloride.

Assertion (A) When common salt is kept open, it absorbs moisture from the air. → True

Reason (R) Common salt contains magnesium chloride → True

Magnesium chloride present in common salt is deliquescent and absorbs moisture from the air. Thus the reason (R) is the correct explanation of the assertion (A).

Thus, Both A and R are true and R is the correct explanation of A.

Hence, "Option 1" is the correct answer.

Additional InformationWhile pure sodium chloride is not deliquescent, common salt often contains impurities , such as magnesium chloride. Magnesium chloride is deliquescent meaning it absorbs moisture from the air and eventually dissolves in it. This explains why common salt becomes moist when exposed to air.