Question

2Al + 6HCl(s) ---------------------------> 2ACl3(s) + 3 H2(g)

how many moles of hydrogen would be obtained if 2.7g of aluminum reacts with excess hydrochloric acid?

Answer 1

$v_{H_2}=\frac{m_{Al}·1.5}{M_{Al}}=\frac{2.7·1.5}{27}=1.5$