8. Thermochemistry

In a reaction energy diagram, which point or segment represents the enthalpy change (ΔH) of the reaction?

Given that the equilibrium constant k for the vaporization of a liquid is 3.2 × 10^{-3} at 0 °C and 8.1 × 10^{-3} at 50 °C, what is the enthalpy of vaporization (ΔH_{vap}) in kJ/mol? (Assume R = 8.314 J/mol·K)

Which statement correctly describes the relationship between the enthalpy of vaporization and the enthalpy of condensation for a substance?

Which one of the following reactions would produce the largest amount of heat per mole of hydrogen?

Which of the following best describes the difference between the heat (q) of a reaction and the reaction enthalpy (ΔH_{rxn})?

In a thermochemical equation carried out at constant pressure, what does the enthalpy of reaction, $\Delta H_{\mathrm{rxn}}$, measure?

Consider the following reaction at 298 K: 2H2(g) + O2(g) → 2H2O(l). Which of the following statements is correct regarding the enthalpy change (ΔH) for this reaction?

Given that the equilibrium constant k for the reaction a(g) ⇌ b(g) is 3.2 × 10^{-3} at 0°C and 8.1 × 10^{-3} at 50°C, what is the enthalpy of vaporization (ΔH_vap) for the process? (Assume R = 8.314 J·mol^{-1}·K^{-1})

Given the following vapor pressure data for a liquid metal at different temperatures, which method would you use to determine the enthalpy of vaporization (ΔH_vap)?Temperature (K): 400, 420, 440, 460Vapor Pressure (atm): 0.12, 0.22, 0.38, 0.65Choose the most appropriate approach:

What is the standard enthalpy change (ΔH°) for the reaction: 2 NO(g) + O2(g) → 2 NO2(g)?

Given the thermochemical equation: 2H2(g) + O2(g) → 2H2O(l)ΔH = -571.6 kJ, what is the heat of reaction (ΔH) for the formation of 1 mole of H2O(l)?

Given the reaction: N_2O(g) + NO_2(g) → 3 NO(g), what is the standard enthalpy change (ΔH°) for this reaction? (Standard enthalpies of formation: ΔH_f°[N_2O(g)] = 82 kJ/mol, ΔH_f°[NO_2(g)] = 34 kJ/mol, ΔH_f°[NO(g)] = 90 kJ/mol)

Which of the following phase changes are associated with q > 0 (heat absorbed by the system)?

What is the standard enthalpy of formation (ΔH_f^ext{°}) value for CO_2(g) in kJ/mol?

Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 0.820 g of naphthalene burns in a bomb calorimeter, the temperature rises from 25.10 °C to 31.56 °C. If the heat capacity of the calorimeter is 5.11 kJ/°C, what is the change in internal energy (ΔErxn) for the combustion of naphthalene?