Consider the following hypothetical reactions: A → B ΔH_I = +60 kJ B → C ΔH_II = -90 kJ (a) Use Hess’s law to calculate the enthalpy change for the reaction A → C.

Under constant-volume conditions, the heat of combustion of benzoic acid (C₆H₅O₆) is 15.57 kJ/g. A 3.500-g sample of sucrose is burned in a bomb calorimeter. The temperature of the calorimeter increases from 20.94 to 24.72 °C. (b) If the size of the sucrose sample had been exactly twice as large, what would the temperature change of the calorimeter have been?

Under constant-volume conditions, the heat of combustion of naphthalene (C₁₀H₈) is 40.18 kJ/g. A 2.50-g sample of naphthalene is burned in a bomb calorimeter. The temperature of the calorimeter increases from 21.50 to 28.83 °C. (c) Suppose that in changing samples, a portion of the water in the calorimeter were lost. In what way, if any, would this change the heat capacity of the calorimeter?

Consider the following hypothetical reactions: A → B ΔH_I = +60 kJ B → C ΔH_II = -90 kJ (b) Construct an enthalpy diagram for substances A, B, and C, and show how Hess's law applies.

Calculate the enthalpy change for the reaction P₄O₆(s) + 2 O₂(g) → P₄O₁₀(s) given the following enthalpies of reaction: P₄(s) + 3 O₂(g) → P₄O₆(s) ΔH = -1640.1 kJ P₄(s) + 5 O₂(g) → P₄O₁₀(s) ΔH = -2940.1 kJ

From the enthalpies of reaction 2 C(s) + O₂(g) → 2 CO(g) ΔH = -221.0 kJ 2 C(s) + O₂(g) + 4 H₂(g) → 2 CH₃OH(g) ΔH = -402.4 kJ Calculate ΔH for the reaction CO(g) + 2 H₂(g) → CH₃OH(g)