Calculate the mass of zinc that has completely reacted with a solution containing 7.3 g of hydrochloric acid.

Let’s write the equation:

Zn + 2HCl = ZnCl2 + H2 – substitution, hydrogen, zinc chloride is formed;
Calculations:
M (Zn) = 65.3 g / mol;

M (HCl) = 36.5 g / mol;

Y (HCl) = m / M = 7.3 / 36.5 = 0.2 mol.

Proportion:
0.2 mol (HCl) – X mol (Zn);

-2 mol -1 mol hence, X mol (Zn) = 0.2 * 1/2 = 0.1 mol.

We find the mass of the original substance:
m (Zn) = Y * M = 0.1 * 65.3 = 6.53 g

Answer: you need zinc weighing 6.53 g