To 10 grams of magnesium was added 15 grams of hydrochloric acid. calculate the amount of released hydrogen

1. Let’s write down the reaction equation:

Mg + 2HCl = MgCl2 + H2.

2. Find the amounts of magnesium and hydrochloric acid:

n (Mg) = m (Mg) / M (Mg) = 10 g / 24 g / mol = 0.417 mol.

n (HCl) = m (HCl) / M (HCl) = 15 g / 36.5 g / mol = 0.41 mol.

3. According to the reaction equation, we find the amount and then the volume of hydrogen (Vm is the molar volume, constant equal to 22.4 l / mol):

The equation shows that hydrochloric acid is in short supply, therefore we decide by its amount.

n (H2) = n (HCl) / 2 = 0.41 mol / 2 = 0.205 mol.

V (H2) = n (H2) * Vm = 0.205 mol * 22.4 L / mol = 4.6 L.

Answer: V (H2) = 4.6 liters.