The molarity of 20.0 mass%  ${\mathrm{H}}_2{\mathrm{SO}}_4$  solution of density  $1.14\mathrm{g}{\mathrm{cm}}^{-3}$ is 

Volume of 100 g solution is $V=\frac{m}{\rho }=\frac{100\mathrm{g}}{1.14\mathrm{g}{\mathrm{cm}}^{-1}}=87.72{\mathrm{cm}}^3$

Amount of sulphuric acid in 100 g solution is  $n=\frac{m}{M}=\frac{20.0\mathrm{g}}{98\mathrm{g}{\mathrm{mol}}^{-1}}=0.207\mathrm{mol}$

Molarity of sulphuric acid is $M=\frac{n}{V}=\frac{0.207\mathrm{mol}}{87.72\times {10}^{-3}{\mathrm{dm}}^3}=2.32\mathrm{mol}{\mathrm{dm}}^{-3}$