I'm having trouble trying to balance this half reaction: P4 + NO3^- ---> H2PO4^- + NO?

Question

i know that P4 ---> H2PO4^- is the oxidation half reaction

and that NO3^- ---> NO is the reduction half reaction.

i think i got the answer but im not sure if this is correct.

38H2O + 3P4 + 5NO3^- ---> 12H2PO4^- + 52H^+ + 5NO.

Please help me if I did it wrong. Thank you :)

Answer 1

As large as those coefficients may seem, I believe that you've balanced the reaction correctly. The forum link I've provided below discusses the above half reactions, and states that "you must add water on the left and H+ on the right," which you've done. Since the coefficients cannot be simplified/reduced further, you have arrived at the balanced reaction.