Question

Find the number of phosphine molecules formed when 5 molecules of $C{a}_3{P}_2$reacts with water. Slaked lime is another product.

Answer 1

1. The chemical formula of phosphine is $P{H}_3$.

2. Phosphine is prepared by the action of a strong base or hot water on white phosphorous / by the reaction of water with calcium phosphide $(C{a}_3{P}_2)$.

. $C{a}_3{P}_2\left(s\right)+6H_{2}O\left(l\right)\to 3Ca{\left(OH\right)}_2+2P{H}_3\left(g\right)$

4. One molecule of $C{a}_3{P}_2$reacts with six molecule of water to produce 2 phosphine molecule and 3 molecule of slaked lime ( calcium hydroxide $Ca{\left(OH\right)}_2$)

5. Therefore the number of phosphine molecule formed when 5 molecule of $C{a}_3{P}_2$reacts with 30 molecules of water is 10.