Find the mass of water required for the complete interaction of 11.2 g of calcium with water.

1. Let’s compose the equation of interaction of calcium with water:

Ca + 2H2O = Ca (OH) 2 + H2 ↑.

2. Find the chemical amount of calcium:

n (Ca) = m (Ca): M (Ca) = 11.2: 40 = 0.28 mol.

3. Determine the amount of water:

n (H2O) = n (Ca) * 2 = 0.28 * 2 = 0.56 mol.

4. Let’s calculate the mass of water required for the reaction:

m (H2O) = n (H2O) * M (H2O) = 0.56 * 18 = 10.08 g.

Answer: 10.08 g.