Firstly, write a balanced equation for the chemical reaction: H\(_2\)SO\(_4\) + 2NaOH → Na\(_2\)SO\(_4\) + 2H\(_2\)O C\(_A\) = 0.5 mol dm\(^{-3}\) V\(_A\) = ? C\(_B\) = 0.1 mol dm\(^{-3}\) V\(_B\) = 25 cm\(^3\) N\(_A\) = 1 N\(_B\) = 2 \(\frac{{C_A}{V_A}}{{C_B}{V_B}}\) = \(\frac{N_A}{N_B}\) V\(_A\) = \(\frac{{C_B}{V_B}{N_A}}{{C_A}{N_B}}\) V\(_A\) = \(\frac{{0.1}\times{25}\times{1}}{{0.5}\times{2}}\) V\(_A\) = 2.5 cm\(^3\)