Question

write in word form: 3 h₂ + p₂ → 2 ph₃
6 atoms of hydrogen react with 2 atoms of phosphorus to produce 6 atoms of ph₃
3 molecules of h₂ react with 1 molecule of p₂ to yield 2 molecules of ph₃
2 molecules of h₂ react with 1 molecule of p₂ to yield 3 molecules of ph₃
3 molecules of h₂ react with 3 molecule of p₂ to make 6 molecules of ph₃

Explanation:

The chemical equation $3H_2 + P_2
ightarrow2PH_3$ shows that the coefficient 3 in front of $H_2$ means 3 molecules of hydrogen gas ($H_2$), the coefficient 1 (implied) in front of $P_2$ means 1 molecule of phosphorus gas ($P_2$), and the coefficient 2 in front of $PH_3$ means 2 molecules of phosphine gas ($PH_3$).

Answer:

B. 3 molecules of $H_2$ react with 1 molecule of $P_2$ to yield 2 molecules of $PH_3$