Calculate ΔG°rxn at 25°C for the reaction: 2CH4(g) → C2H6(g) + H2(g). Given the following standard Gibbs free energies of formation: ΔG°f(CH4) = -50.8 kJ/mol, ΔG°f(C2H6) = -32.8 kJ/mol, ΔG°f(H2) = 0 kJ/mol.

What is the enthalpy change (ΔH) for the dissolution of 2.50 g of substance X in water, given that the temperature of the solution increases from 12.0 °C to 27.0 °C?

A sample of steam with a mass of 0.521 g at a temperature of 100 °C condenses into an insulated container holding 4.45 g of water at 2.0 °C. For water, ΔHvap = 40.7 kJ/mol and Cwater = 4.18 J/(g·°C). Assuming that no heat is lost, what is the final temperature of the water in the container?

An 8.5 g ice cube is placed into 255 g of water. Calculate the temperature change in the water upon the complete melting of the ice. Assume that all of the energy required to melt the ice comes from the water. The enthalpy of fusion (ΔH_fusion) is 6.02 kJ/mol. What is the temperature change in the water?

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?

Calculate the enthalpy change (ΔH°) for the following reaction at 25 °C using the given standard enthalpies of formation (ΔfH°) in kJ/mol: 2H2(g) + O2(g) → 2H2O(l). Given: ΔfH°[H2(g)] = 0, ΔfH°[O2(g)] = 0, ΔfH°[H2O(l)] = -285.8.

Calculate the value of ΔH° in kJ for the following reaction: 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l), given the following standard enthalpies of formation: ΔHf°[NH3(g)] = -45.9 kJ/mol, ΔHf°[NO(g)] = 90.3 kJ/mol, ΔHf°[H2O(l)] = -285.8 kJ/mol.

Calculate ΔrH for the reaction: CH4(g) + 4 Cl2(g) → CCl4(g) + 4 HCl(g) using the given ΔfH values: CH4(g) ΔfH = -74.6 kJ/mol, CCl4(g) ΔfH = -95.7 kJ/mol, and HCl(g) ΔfH = -92.3 kJ/mol.

Choose the thermochemical equation that illustrates ΔH°f for K2SO4(s).