Em tham khảo nha:
\(\begin{array}{l}
{n_{Zn}} = \dfrac{{6,5}}{{65}} = 0,1\,mol\\
a)\\
{n_{{H_2}S{O_4}}} = 0,15 \times 1 = 0,15\,mol\\
Zn + {H_2}S{O_4} \to ZnS{O_4} + {H_2}\\
{n_{Zn}} < {n_{{H_2}S{O_4}}} \Rightarrow {H_2}S{O_4} \text{ dư }\\
{n_{{H_2}}} = {n_{Zn}} = 0,1\,mol\\
{V_{{H_2}}} = 0,1 \times 22,4 = 2,24l\\
b)\\
{n_{{H_2}S{O_4}}} = \dfrac{{25 \times 19,6\% }}{{98}} = 0,05\,mol\\
Zn + {H_2}S{O_4} \to ZnS{O_4} + {H_2}\\
{n_{Zn}} > {n_{{H_2}S{O_4}}} \Rightarrow Zn \text{ dư }\\
{n_{{H_2}}} = {n_{{H_2}S{O_4}}} = 0,05\,mol\\
{V_{{H_2}}} = 0,05 \times 22,4 = 1,12l
\end{array}\)