Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. In the first step, nitrogen and hydrogen react to form ammonia: N₂(g) + 3 H₂(g) → 2NH3(g) ΔΗ= -92. kJ In the second step, ammonia and oxygen react to form nitric acid and water: NH3(g) + 2O₂(g) HNO3(g) + H₂O(g) Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. Round your answer to the nearest kJ. KJ AH=-330. kJ X

Q1

Diborane (B2H6(g)) is a highly reactive boron hydride, which was at one time considered as a possible rocket fuel for the US space program. Write a balanced thermochemical equation for the formation of diborane from the elements using the following information:   2 B(s) + 3/2 O2(g) ---> B2O3(s)                                  ΔH = -1273 kJ/rxn B2H6(g) + 3 O2(g) ---> B2O3(s) + 3 H2O(g)                    ΔH = -2035 kJ/rxn H2(g) + 1/2 O2(g) ---> H2O(l)                                     ΔH = -286 kJ/rxn H2O(l) ---> H2O(g)                                                    ΔH =  +44 kJ/rxn

61. Consider the thermochemical equation for the combustion of acetone (CH,O), the main ingredient in nail polish remover: C;H,O(l) + 4 O,(g) 3 CO2(g) + 3 H,O(g) A,H° = -1790 kJ mol If a bottle of nail polish remover contains 177 mL of acetone, how much heat is released by its complete combustion? The density of acetone is 0.788 g mL.