How many grams of calcium hydroxide is formed when 11.2 grams of calcium oxide is dissolved in water?

Given:
m (CaO) = 11.2 g

Find:
m (Ca (OH) 2) -?

Solution:
1) H2O + CaO => Ca (OH) 2;
2) M (CaO) = Mr (CaO) = Ar (Ca) * N (Ca) + Ar (O) * N (O) = 40 * 1 + 16 * 1 = 56 g / mol;
3) n (CaO) = m (CaO) / M (CaO) = 11.2 / 56 = 0.2 mol;
4) n (Ca (OH) 2) = n (CaO) = 0.2 mol;
5) M (Ca (OH) 2) = Mr (Ca (OH) 2) = Ar (Ca) * N (Ca) + Ar (O) * N (O) + Ar (H) * N (H) = 40 * 1 + 16 * 2 + 1 * 2 = 74 g / mol;
6) m (Ca (OH) 2) = n (Ca (OH) 2) * M (Ca (OH) 2) = 0.2 * 74 = 14.8 g.

Answer: The mass of Ca (OH) 2 is 14.8 g.