`3.0` molal `NaOH` solution has a density of `1.110 g//mL`. The molarity of the solution is:

Options

A. `3.0504`
B. `3.64`
C. `3.05`
D. `2.9732`

Answer

D

Explanation

3 molal solution is prepared by dissolving 3 moles (40 `xx` 3 = 120 g) of NaOH in 1000 g of water.
Total mass of such solution containing 3 moles of the solute `=1000+120=1120g`
Density of this solution = 1.110 g /mL
Total volume of the solution `=(1120)/(1.11)`
= 1009 mL = 1.009 L
Thus, 3 moles of NaOH are present in 1.009 L of solution.
So, no. of moles present in 1 L of the solution `=3xx(1)/(1.009)=2.973`.