Calcium phosphate Ca3P2 reacts with water, resulting in the formation of phosphine gas PH3 and calcium hydroxide

Calcium phosphate Ca3P2 reacts with water, resulting in the formation of phosphine gas PH3 and calcium hydroxide Ca (OH) 2. What is the mass of Ca (OH) 2 and what volume of PH3 can be obtained from 9.1g

Given:
m (Ca3P2) = 9.1 g

To find:
m (Ca (OH) 2) -?
V (PH3) -?

Decision:
1) Ca3P2 + 6H2O => 2PH3 + 3Ca (OH) 2;
2) M (Ca3P2) = 182 g / mol;
M (Ca (OH) 2) = 74 g / mol;
3) n (Ca3P2) = m (Ca3P2) / M (Ca3P2) = 9.1 / 182 = 0.05 mol;
4) n (Ca (OH) 2) = n (Ca3P2) * 3 = 0.05 * 3 = 0.15 mol;
5) m (Ca (OH) 2) = n (Ca (OH) 2) * M (Ca (OH) 2) = 0.15 * 74 = 11.1 g;
6) n (PH3) = n (Ca3P2) * 2 = 0.05 * 2 = 0.1 mol;
7) V (PH3) = n (PH3) * Vm = 0.1 * 22.4 = 2.24 liters.

Answer: The mass of Ca (OH) 2 is 11.1 g; volume PH3 – 2.24 l.