8. Thermochemistry

Consider the following generic reaction: A + 2 B → 3 C + D; ΔH = 623 kJ. What would be the value of ΔH for the following reaction: 1/3 A + 2/3 B → C + 1/3 D?

When 50.0 mL of 0.400 M Ca(NO3)2 is added to 50.0 mL of 0.800 M NaF, CaF2 precipitates, as shown in the net equation below. The initial temperature of the solution is 30.0 °C. Assuming that the reaction goes to completion, and that the resulting solution has a mass of 100.0 g, what is the enthalpy change (ΔH) for the reaction if the final temperature of the solution is 25.0 °C?

What is the standard enthalpy change for the combustion of one mole of benzene (C6H6) based on the given thermochemical equation: 2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(l) ΔHrxn° = -6534 kJ?

Which one of the following reactions would produce the largest amount of heat per mole of oxygen (O_2) consumed?

Given the reaction: 2 H_2S(g) + 3 O_2(g) → 2 SO_2(g) + 2 H_2O(g), what is the standard enthalpy change (ΔH°) for this reaction? (Use the following standard enthalpies of formation: ΔH_f°(H_2S(g)) = -20.6 kJ/mol, ΔH_f°(O_2(g)) = 0 kJ/mol, ΔH_f°(SO_2(g)) = -296.8 kJ/mol, ΔH_f°(H_2O(g)) = -241.8 kJ/mol)

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

In a reaction energy diagram, which part of the diagram represents the change in enthalpy (ΔH) for the reaction?

For the reaction 2NO(g) + O2(g) → 2NO2(g), the enthalpy change ΔH is negative and the entropy change ΔS is negative. The forward reaction is thermodynamically favored at which of the following temperatures?

A solid salt dissolves in water according to the following thermochemical equation: NaCl(s) → Na^+(aq) + Cl^-(aq); ΔH = +3.9 kJ/mol. Which statement correctly describes the enthalpy of solution for NaCl(s)?

Given the thermochemical equation CH_4(g) + 2 O_2(g) → CO_2(g) + 2 H_2O(l); ΔH = -890 kJ, what is the enthalpy change (ΔH) when 530 g of methane (CH_4) is combusted?

What is the standard enthalpy change (ΔH°) for the reaction: CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)?

Which of the following reactions represents the standard enthalpy of formation (ΔH_f^∘) for water (H_2O(l))?

Which of the following is a correctly written thermochemical equation?

For which one of the following reactions is the value of ΔH_rxn equal to ΔH_f for the product?

The enthalpy of formation (ΔH_f) of carbon dioxide is negative. Which statement is true?