8. Thermochemistry

Using average bond energies and the standard enthalpy of formation of C(g) (718.4 kJ/mol), estimate the standard enthalpy of formation of gaseous benzene, C6H6(g). Which of the following values is closest to the correct estimate?

Use standard enthalpies of formation to calculate ΔH°_rxn for the following reaction: C(s) + H₂O(g) → CO(g) + H₂(g). Given the standard enthalpies of formation: ΔH°_f [C(s)] = 0 kJ/mol, ΔH°_f [H₂O(g)] = -241.8 kJ/mol, ΔH°_f [CO(g)] = -110.5 kJ/mol, ΔH°_f [H₂(g)] = 0 kJ/mol.

Use standard enthalpies of formation to calculate ΔHºrxn for the following reaction: 2H2S(g) + 3O2(g) → 2H2O(l) + 2SO2(g). Which of the following is the correct value for ΔHºrxn?

Use standard enthalpies of formation to calculate ΔH°rxn for the following reaction: CH4(g) + 2O2(g) → CO2(g) + 2H2O(g). Given the following standard enthalpies of formation: CH4(g) = -74.8 kJ/mol, CO2(g) = -393.5 kJ/mol, H2O(g) = -241.8 kJ/mol, O2(g) = 0 kJ/mol.

Use standard enthalpies of formation to calculate ΔH°rxn for the following reaction: N2O4(g) + 4H2(g) → N2(g) + 4H2O(g). Which of the following is the correct ΔH°rxn value?

Use standard enthalpies of formation to calculate ΔH°_rxn for the following reaction: CaO(s) + CO2(g) → CaCO3(s). Which of the following is the correct ΔH°_rxn value?

Use standard enthalpies of formation to calculate ΔH⁰_rxn for the following reaction: C(s) + H₂O(g) → CO(g) + H₂(g). Which of the following is the correct value for ΔH⁰_rxn?

Use standard enthalpies of formation to calculate ΔHᵣₓₙ for the following reaction: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g). Given the standard enthalpies of formation: CH₄(g) = -74.8 kJ/mol, O₂(g) = 0 kJ/mol, CO₂(g) = -393.5 kJ/mol, H₂O(g) = -241.8 kJ/mol.

Use standard enthalpies of formation to calculate ΔH⁰_rxn for the following reaction: N2O4(g) + 4H2(g) → N2(g) + 4H2O(g). Given the standard enthalpies of formation: ΔH⁰_f [N2O4(g)] = 9.16 kJ/mol, ΔH⁰_f [H2(g)] = 0 kJ/mol, ΔH⁰_f [N2(g)] = 0 kJ/mol, ΔH⁰_f [H2O(g)] = -241.8 kJ/mol.

Using the information below, calculate the enthalpy change (ΔH°rxn) for the following reaction: CH4 (g) + 4 Cl2 (g) → CCl4 (g) + 4 HCl (g). Given the standard enthalpy of formation (ΔHf°) values: CH4 (g) = -75 kJ/mol, CCl4 (g) = -96 kJ/mol, and HCl (g) = -92 kJ/mol.

What is the total change in enthalpy when 25.0 g of solid ethanol (C2H5OH) at -125 °C is converted to liquid ethanol at -80 °C? The table below provides physical and thermochemical data for ethanol. Normal melting point: -114 °C. Assume the specific heat capacities and enthalpy of fusion are known.

What is the standard enthalpy change (∆Hrxn) for the reaction 2 CHCl3(l) → 2 C(s) + H2(g) + 3 Cl2(g) given the standard enthalpy of formation of CHCl3(l) is -134.1 kJ/mol?

When 2.275 g of anthracene, C14H10, is combusted in a bomb calorimeter with a water jacket containing 500.0 g of water, the temperature of the water increases by 43.15°C. Assuming the specific heat of water is 4.18 J/(g°C), and that the calorimeter absorbs no heat, what is the enthalpy change (ΔH) for the combustion of anthracene in kJ/mol?

When 5.60 g of solid sodium reacts with excess fluorine gas to form sodium fluoride, 13.8 kJ of heat is evolved at standard state conditions. What is the standard enthalpy of formation (ΔH⁰f in kJ/mol) of solid sodium fluoride?

Which equation represents the standard enthalpy of formation, ΔH°f, for CHCl3(l)?