Using values from Appendix C, calculate the value of H for each of the following reactions: (a) CaO(s) + 2 HF(g) → CaF₂(s) + H₂O(g) (b) Fe₂O₃(s) + 3 C(s) → 2 Fe(s) + 3CO(g) (c) 2 CO(g) + 2 NO(g) → N₂(s) + 2 CO₂(g) (d) 4 NH₃(g) + 5 O₂(g) → 4 NO(g) + 6 H₂Og)

Acetylene (C₂H₂(g)) is used for welding because oxyacetylene is the hottest burning common fuel gas. Using standard enthalpies of formation, calculate the quantity of heat produced when 10 g of acetylene is completely combusted in air under standard conditions.

Calcium carbide (CaC₂) reacts with water to form acetylene (C₂H₂) and Ca(OH)₂. From the following enthalpy of reaction data and data in Appendix C, calculate H°_f for CaC₂(s): CaC₂(s) + 2 H₂O(l) → Ca(OH₂)(s) + C₂H₂(g) ΔH° = -127.2 kJ

Gasoline is composed primarily of hydrocarbons, including many with eight carbon atoms, called octanes. One of the cleanest–burning octanes is a compound called 2,3,4- trimethylpentane, which has the following structural formula: The complete combustion of one mole of this compound to CO₂(g) and H₂O(g) leads to ΔH° = -5064.9 kJ. (b) By using the information in this problem and data in Table 5.3, calculate H°f for 2,3,4-trimethylpentane.

Complete combustion of 1 mol of acetone (C₃H₆O) liberates 1790 kJ: C₃H₆O(l) + 4 O₂(g) → 3 CO₂(g) + 3 H₂O(l) ΔH° = -1790 kJ Using this information together with the standard enthalpies of formation of O₂(g), CO₂(g), and H₂O(l) from Appendix C, calculate the standard enthalpy of formation of acetone.