13 grams of zinc was dissolved in hydrochloric acid. How much hydrogen will be released?

Given:

m (Zn) = 13 g.

To find:

V (H2) =?

Solution:

1) We compose the equation of the chemical reaction:

Zn + 2HCl = ZnCl2 + H2.

2) The formula for solving the problem: m: M = V: Vm, hence V = (m x Vm): M.

3) Find the molecular weight of zinc using the periodic table:

M (Zn) = 65 g / mol.

4) Vm is a constant value and is equal to 22.4 l / mol.

Vm (H2) = 22.4 L / mol.

5) 13 g: 65 g / mol = x L: 22.4 L / mol,

x = (13 x 22.4): 65 = 4.48 liters.

Answer: V (H2) = 4.48 liters.