Question

Predict the formula of the gas produced when sodium phosphide, Na3P(s), is treated with water.

Answer 1

The answer to your question is
PH3 (g)

Answer 2

Answer:

The formula of the gas produced is $PH_3$.

Explanation:

Whenever metal phosphides reacts with water they form phosphine gas and alkaline solution of metal hydroxide.

$M_3P_x(s)+3xH_2O(l)\rightarrow 3M(OH)_x(aq)+xPH_3(g)$

So, when sodium phosphide is treated with water it gives phosphine gas and sodium hydroxide solution as a product.

$Na_3P(s)+3H_2O(l)\rightarrow 3NaOH(aq)+PH_3(g)$

The formula of the gas produced is $PH_3$.