STD 11 - 3. Classification of elements and periodicity in properties — NEET STD 11 Science — Question

$R =0.083\, L$ bar $K ^{-1} \,mol ^{-1}$ ) (Nearest integer)

Assertion $(A) :$ At $10^{\circ} C$, the density of a $5\, M$ solution of $KCl$ [atomic masses of $K$ and $Cl$ are $39$ and $35.5\, g \,mol ^{-1}$ ]. The solution is cooled to $-21^{\circ} C$. The molality of the solution will remain unchanged.

Reason $(R):$ The molality of a solution does not change with temperature as mass remains unaffected with temperature.

In the light of the above statements, choose the correct answer from the options given below