32.7 g Zn
Explanation:
First convert the amount of gas into moles:
11.2 L H2 × (1 mol H2/22.4 L H2) = 0.500 mol H2
Then use the molar ratio to find the amount of zinc necessary to produce the amount of gas above:
0.500 mol H2 × (1 mol Zn/1 mol H2)
= 0.500 mol Zn
Now use the molar mass of zinc to find the number of grams of zinc for the reaction to occur:
0.500 mol Zn × (65.38 g Zn/1 mol Zn)
= 32.7 g Zn
