question_answer 76)

  The density of 3 molal solution of \[NaOH\] is \[1.110\,g\,m{{L}^{-1}}\].Calculate the molarity of the solution.

Answer:

  3 mol \[NaOH\] is dissolved in 1000 g solvent. Thus, Mass of solution \[=1000+40\times 3=1120g\] Volume of solution \[=\frac{Mass}{Density}=\frac{1120}{1.11}=1009mL.\] Molarity of solution can be calculated as: \[M=\frac{{{w}_{B}}\times 1000}{{{m}_{B}}\times V}=\frac{120\times 1000}{40\times 1009}=2.97\]