Question

A solution is prepared by dissolving 20 g NaOH in distilled water to give 200 mL of solution. Calculate the molarity of solution

• A. 2.28 M
• B. 10.7 M
• C. 3.65 M
• D. 2.5 M

Answer 1

The correct option is D 2.5 M

Molar mass of NaOH = 23 + 16 + 1
= 40 g/ mol
$MolesofNaOH=\frac{20}{40}$ = 0.5 mol
$Molarity=\frac{0.5}{200}\times 1000$ = 2.5 M