Answer;
= 0.28 L of PH₃
Explanation and solution;
Phosphorus and hydrogen can be combined to form phosphine
P₄(s) + 6H₂(g) → 4PH₃(g)
From the equation; we want to determine how many L of phosphine will be formed from 0.42 L of hydrogen;
1 mole of a gas occupies 22.4 L at STP
Therefore; moles of H2 = 0.42 L/22.4 L
The mole ratio of H2 to PH3 is 4 moles :6 moles
Thus;
Moles of PH3 = 0.42/22.4 × 4/6
Hence;
Volume of PH3 = 0.42/22.4 × 4/6 × 22.4/1
= 0.28 L
Thus; we form 0.28 L of phosphine