Magnesium (24.48g) reacts with hydrochloric acid (xg) to produce hydrogen gas (2.04g) and magnesium chloride (96.90g). How much hydrogen chloride was used in the reaction?

Mass = 73.73 g

Explanation:

Given data:

Mass of Mg used = 24.48 g

Mass of HCl used = ?

Mass of hydrogen gas produced = 2.04 g

Mass of Magnesium chloride produced = 96.90 g

Solution:

Chemical equation:

Mg + 2HCl   →    MgCl₂ + H₂

Number of moles of Mg:

Number of moles = mass/ molar mass

Number of moles = 24.48 g/ 24.305 g/mol

Number of moles = 1.01 mol

Now we will compare the moles of Mg with HCl from balance chemical equation.

                              Mg             :            HCl

                               1                ;               2

                            1.01              :           2/1× 1.01 = 2.02 mol

Mass of HCl react:

Mass = number  of moles × molar mass

Mass =  2.02 ×  36.5 g/mol

Mass = 73.73 g

Magnesium (24.48g) reacts with hydrochloric acid (74.46 g) to produce hydrogen gas (2.04g) and magnesium chloride (96.90g).

Let's consider the following balanced equation.

24.48 g of magnesium react with an unknown mass of hydrochloric acid to produce 2.04 g of hydogen gas and 96.90 g of magnesium chloride.

According to Lavoisier's law of conservation of mass, matter is not created nor destroyed over the course of a chemical reaction. As a consequence, the sum of the masses of the reactants must be equal to the sum of the masses of the products.

Magnesium (24.48g) reacts with hydrochloric acid (74.46 g) to produce hydrogen gas (2.04g) and magnesium chloride (96.90g).

You can learn more about Lavoisier's law here: link

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