Question

Calculate the molarity of 30% (w/W) NaOH solution, if the density of the solution is 1.05 g/cc.

• A. 7.5 M
• B. 3.75 M
• C. 7.88 M
• D. 3.94 M

Answer 1

The correct option is A 7.5 M

30% w/v of $NaOH$ corresponds to 30 gm of $NaOH$ in 100 ml solution.

Amount of $NaOH$ present in 1000 ml solution is $300gm$.

Molarity of $NaOH=\frac{300}{40}\times \frac{1000}{1000}=7.5M$.

Hence, option A is correct.