Zinc weighing 45.5 g was heated with 28 g of NaOH. The volume of released hydrogen is …

Zinc, when fused with alkalis, forms zincates:

The reaction is described by the following chemical reaction equation:

Zn + 2NaOH → Na2ZnO2 + H2;

Let’s find the chemical amount of zinc. To do this, we divide its weight by the mass of 1 mole of metal.

N Zn = 45.5 / 65 = 0.7 mol;

Let’s calculate the molar amount of alkali. To do this, we divide its weight by the mass of 1 mole of alkali.

M NaOH = 23 + 16 + 1 = 40 grams / mol;

N NaOH = 28/40 = 0.7 mol;

With 0.7 mol of alkali, 0.35 mol of metal will react. This will release 0.35 mol of hydrogen

Let’s calculate the volume of hydrogen. To this end, we multiply the amount of substance by the volume of 1 mole of gas (which is 22.4 liters).

V H2 = 0.35 x 22.4 = 7.84 liters;