Question

The molarity of a solution containing 50 g of NaCl in 500 g of a solution and having a density of $0.936g/c{m}^3$ is :

• A. 1.5 M
• B. 1.4 M
• C. 1.8 M
• D. 1.2 M

Answer 1

The correct option is B 1.4 M

Total mass of solution = 500+50 = 550 g

density = $\frac{mass}{volume}$

volume = $\frac{550}{0.936}$ ml = 587.6 ml

Molarity = $\frac{givenweight\ast 1000}{molecularweight\ast volume\left(ml\right)}$

Molarity = $\frac{50\ast 1000}{58.5\ast 587.6}$

molarity = 1.45 M