The density of a solution containing $13\%$  by mass of sulphuric acid is$1.09\text{ g/mL}$ . Then, the molarity of the solution is

Mass percentage of sulphuric acid , $x=13\%$

Density,$\text{d}=1.09\text{ g}/\text{mL}$

GMW of ${\text{H}}_2{\text{SO}}_4=98$

The formula used to find molarity is

            $\text{M}=\frac{10\times \text{d}\times x}{\text{GMW}}$  

$\text{Molarity}=\frac{10\times 1.09\times 13}{98}=1.445\text{M}$