How does elemental phosphorus react to give PH_3 and HPO_2^(-) under basic conditions?

1 Answer
Dec 19, 2016

This is a disproportionation reaction. Elemental phosphorus is reduced and oxidized.

Explanation:

1/4P_4+3H^+ + 3e^(-) rarrPH_3 "(i) reduction"

1/4P_4 + 2HO^(-) rarr HPO_2^(-) +H^(+) + 2e^(-) " (ii) oxidation"

Overall: 2xx(i) + 3xx(ii)

5/4P_4+6H_2O rarr2PH_3 +3HPO_2^(-) +3H^(+)

I will add 3xxHO^- to each side of the equation to represent that the reaction is performed in basic conditions:

5/4P_4+3HO^(-) + 3H_2O rarr2PH_3 +3HPO_2^(-)

Is this balanced with respect to mass and charge?