Question

The molarity of the solution containing $2.8\%$ (m/V) solution of KOH is:

• A. $M/10$
• B. $M/2$
• C. $M/5$
• D. $1$M

Answer 1

The correct option is B $M/2$

$2.8$% mass by volume implies $2.8g$ per $100ml$ of solution.

Molarity $=\frac{Moles}{Vol\left(inlit\right)}$

Molar mass of $KOH=56gm$

Number of moles $=\frac{2.8}{56}=0.05$

Molarity $=\frac{0.05}{0.1}=0.5=\frac{1}{2}M$

Hence, option B is correct.