Calculate the mass of the precipitate obtained by the interaction: 7.4 g of calcium hydroxide with sodium carbonate?

Let’s write the reaction equation:

Ca (OH) 2 + Na2CO3 = CaCO3 ↓ + 2NaOH

Let’s find the amount of substance Ca (OH) 2:

v (Ca (OH) 2) = m (Ca (OH) 2) / M (Ca (OH) 2) = 7.4 / 74 = 0.1 (mol).

According to the reaction equation, from 1 mol of Ca (OH) 2, 1 mol of CaCO3 is formed, therefore:

v (CaCO3) = v (Ca (OH) 2) = 0.1 (mol).

Thus, the mass of the formed calcium carbonate precipitate is:

m (CaCO3) = v (CaCO3) * M (CaCO3) = 0.1 * 100 = 10 (g).

Answer: 10 g.