Em tham khảo nha :

\(\begin{array}{l}
7)\\
a)\\
{H_2}S{O_4} + 2KOH \to {K_2}S{O_4} + 2{H_2}O\\
b)\\
{n_{{H_2}S{O_4}}} = 0,2 \times 1 = 0,2mol\\
{n_{KOH}} = 2{n_{{H_2}S{O_4}}} = 0,4mol\\
{m_{KOH}} = 0,4 \times 56 = 22,4g\\
{m_{{\rm{dd}}KOH}} = \dfrac{{22,4 \times 100}}{6} = 373,3g\\
{V_{KOH}} = \dfrac{{373,3}}{{1,048}} = 356,2ml\\
8)\\
a)\\
N{a_2}O + {H_2}O \to 2NaOH\\
b)\\
{n_{N{a_2}O}} = \dfrac{{15,5}}{{62}} = 0,25mol\\
{n_{NaOH}} = 2{n_{N{a_2}O}} = 0,5mol\\
{C_{{M_{NaOH}}}} = \dfrac{{0,5}}{{0,5}} = 1M\\
c)\\
{H_2}S{O_4} + 2NaOH \to N{a_2}S{O_4} + 2{H_2}O\\
{n_{{H_2}S{O_4}}} = \dfrac{{{n_{NaOH}}}}{2} = 0,25mol\\
{m_{{H_2}S{O_4}}} = 0,25 \times 98 = 24,5g\\
{m_{{\rm{dd}}{H_2}S{O_4}}} = \dfrac{{24,5 \times 100}}{{20}} = 122,5g\\
{V_{{H_2}S{O_4}}} = \dfrac{{122,5}}{{1,14}} = 107,5ml
\end{array}\)