posted by samantha .
Al(s) + HCl(aq) AlCl3(aq) + H2(g)
Zn(s) + HCl(aq) ZnCl2(aq) + H2(g)
Consider the unbalanced equations above. A 0.250 g sample of a mixture of aluminum and zinc metal is reacted with an excess of hydrochloric acid. Both metals react with hydrochloric acid. The sample produces 210.2 mL of hydrogen gas at STP.
(a) What is the mass percent aluminum in the sample?
(b) What is the mass percent zinc in the sample?