Multiple Choice
Using the given reactions, calculate the standard free energy of formation, ΔG°f, for phosphoric acid (H3PO4). Given: 1. P4 (s) + 5 O2(g) → P4O10(s) ΔG° = -2697.0 kJ/mol 2. 2 H2(g) + O2(g) → 2 H2O(g) ΔG° = -457.18 kJ/mol 3. 6 H2O(g) + P4O10(s) → 4 H3PO4(l) ΔG° = ?