240 g of metal powder consisting of 35% zinc and 65% copper was poured

240 g of metal powder consisting of 35% zinc and 65% copper was poured with excess hydrochloric acid. determine the mass of the evolved gas.

Copper does not interact with hydrochloric acid.

Zinc dissolves in hydrochloric acid, the reaction is described by the following chemical equation:

Zn + 2HCl = ZnCl2 + H2;

Let’s calculate the chemical amount of zinc. To do this, we divide its weight by the molar weight of elemental zinc.

M Zn = 65 grams / mol;

N Zn = 240 x 0.35 / 65 = 1.2923 mol;

The same amount of hydrogen will be released.

Let’s determine its weight.

To this end, we multiply the amount of substance by the weight of 1 mole of hydrogen gas.

M H2 = 2 grams / mol;

m H2 = 2 x 1.2923 = 2.585 grams;