Question

$3.0g$ of a salt of molecular weight $30$ is dissolved in $250g$ water. The molarity of the solution is ............

Answer 1

Molarity $=\frac{\text{ Number of moles of solute }}{\text{ Volume of solution in litre }}$
$=\frac{\text{ Weight of solute }}{\text{ Molar mass }}\times \frac{1000}{\text{ Volume in mL }}$
$=\frac{3}{30}\times \frac{1000}{250}=0.4M$