Respuesta :

Hi! I hope this helps, here’s the answer.

2NH3 + 3/2O2 --> N2 + 3H2O 

NH3 + 3/4O2 --> 1/2N2 + 3/2H2O 

Here, the sign of deltaS^0 is one molecule (^0) thus, the coefficient of NH3 should be ONE.