Question

When 11.2 liters of hydrogen gas is made by adding zinc to sulfuric acid, what mass

of zinc is needed?
Zn + H2SO4 -> H2 + ZnSO4

Answer 1

32.7 g Zn

Step-by-step 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