Chapter 5, Problem 92QAP

A 0.2500-g sample of an Al-Zn alloy reacts with HCl to form hydrogen gas:

$\begin{array}{l}\text{Al}\left(s\right)+3{\text{H}}^{+}\left(aq\right)\to {\text{Al}}^{3+}\left(aq\right)+\frac{3}{2}{\text{H}}_2\left(g\right)\\ \text{Zn}\left(s\right)+2{\text{H}}^{+}\left(aq\right)\to {\text{Zn}}^{2+}\left(aq\right)+{\text{H}}_2\left(g\right)\end{array}$

The hydrogen produced has a volume of 0.147 L at 25°C and 755 mm Hg. What is the percentage of zinc in the alloy?