How many grams of hydrogen can be obtained by acting with perchloric acid on 13 g of zinc?

To solve this problem, we write down given: m (Zn) = 13 g. Zinc reacted with hydrochloric acid (HCl)

Find: the mass of the formed hydrogen.

Decision:

To solve this problem, we write down the reaction equation for the interaction of zinc with hydrochloric acid.

Zn + HCl = ZnCl2 + H2

Let’s arrange the coefficients.

Zn + 2HCl = ZnCl2 + H2

Let’s calculate the molar masses of zinc and hydrogen.

M (Zn) = 65 g / mol

M (H2) = 1 * 2 = 2 g / mol

Over the zinc we write 13 g, and under the zinc – 65 g.

We write x g over hydrogen, and 2 g under hydrogen.

Let’s compose and solve the proportion:

x = 13 * 2/65 = 0.4 g

Answer: 0.4 g