30 g of a copper-zinc alloy was treated with a sulfuric acid solution. In this case, 4.4 liters of hydrogen

30 g of a copper-zinc alloy was treated with a sulfuric acid solution. In this case, 4.4 liters of hydrogen were released. Calculate the mass fraction of inca (%) in this alloy.

Zn + H2SO4 = ZnSO4 + H2.

First, let’s determine the amount of hydrogen substance.

n = V / Vm.

n = 4.4 L / 22.4 L / mol = 0.2 mol.

Next, use the reaction equation to determine the amount of zinc.

X mol Zn – 0.2 mol H2.

1 mol Zn – 1 mol H2.

X = 1 * 0.2: 1 = 0.2 mol.

Next, we determine the mass of zinc.

m (Zn) = 0.2 mol * 65 g / mol = 13 g.

Next, you should determine the mass fraction of zinc in this alloy. To do this, it is necessary to divide the mass of zinc by the mass of the alloy. We write down the solution.

W = 13/30 * 100% = 43.3%.

Answer: W = 43.3%.