Calculate the mass of salt that will result from the interaction of magnesium with 100 g of 10% hydrochloric acid.

| April 2, 2021 | education

Find the mass of hydrochloric acid in the solution.

The mass fraction of a substance is calculated by the formula:

W = m (substance): m (solution) × 100%,

m (substance) = (m (solution) × W): 100%,

m (substance) = (100 g × 10%): 100% = 10 g.

Let’s find the amount of hydrochloric acid substance by the formula:

n = m: M.

M (HCl) = 1 + 35 = 36 g / mol.

n = 10 g: 36 g / mol = 0.28 mol.

Let’s compose the reaction equation, find the quantitative ratios of substances.

Mg + 2HCl = MgCl2 + H2 ↑.

According to the reaction equation, for 2 mol of acid there is 1 mol of magnesium chloride (salt). Substances are in quantitative ratios of 2: 1.

The amount of salt substance will be 2 times less than acid.

2n (HCl) = n (MgCl2) = 0.28: 2 = 0.14 mol.

Let’s find the mass of magnesium chloride.

m = n × M,

M (MgCl2) = 24 + 70 = 94 g / mol.

m = 0.14 mol × 94 g / mol = 13.16 g.

Answer: 13.16 g.



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