The correct option is A 3H2O, 3OH−
0P4(s)+OH−(aq)→−3P+1H3(g)++1H2+1P−2O−2(aq)
Total decrease in O.N of P4 in PH3=12.
Total increase in O.N of P4 in H2PO−2=1×4=4
To balance increase and decrease in O.N, multiply PH3 by 1 and H2PO−2 by 3.
P4(s)+OH−(aq)→PH3(g)+3H2PO−2(aq)
To balance O atoms, we have to multiply OH− by 6, we get
P4(s)+6OH−(aq)→PH3(g)+3H2PO−2(aq)
To balance H atoms
P4(s)+6OH−+3H2O→PH3(g)+3H2PO−2(aq)+3OH−
P4+3OH−+3H2O→PH3(g)+3H2PO−2(aq)