80g of magnesium reacts with hydrochloric acid. Determine the mass of the salt obtained.

Let’s write the reaction equation:

Mg + 2HCl = MgCl2 + H2 ↑

Let’s find the amount of magnesium substance:

v (Mg) = m (Mg) / M (Mg) = 80/24 (mol).

According to the reaction equation, from 1 mol of Mg, 1 mol of MgCl2 is formed, therefore:

v (MgCl2) = v (Mg) = 80/24 (mol).

Thus, the mass of the obtained magnesium chloride salt is:

m (MgCl2) = v (MgCl2) * M (MgCl2) = (80/24) * 95 = 316. (6) = 316.7 (g).