Using given data, calculate the change in Gibbs free energy for each of the following reactions. In each case indicate whether the reaction is spontaneous at 298 K under standard conditions. P4O10(s) + 16H2(g) -> 4PH3(g) + 10H2O(g) Gibbs free energy for P4O10(s) is -2675.2 kJ/mol Gibbs free energy for PH3(g) is 13.4 kJ/mol Gibbs free energy for H2O(g) is -228.57 kJ/mol