8. Thermochemistry
Enthalpy of Formation
- Multiple ChoiceUsing the standard enthalpies of formation, calculate ΔH°rxn for the reaction: CaO(s) + CO2(g) → CaCO3(s). Given: ΔH°f [CaO(s)] = -635.1 kJ/mol, ΔH°f [CO2(g)] = -393.5 kJ/mol, ΔH°f [CaCO3(s)] = -1206.9 kJ/mol.
- Multiple ChoiceUsing standard thermodynamic data, calculate ΔH°rxn for the following:
2 C2H2 (g) + 5 O2 (g) → 4 CO2 (g) + 2 H2O (l)
- Multiple Choice
The oxidation of ammonia is illustrated by the following equation:
4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (g)
Calculate the enthalpy of reaction,ΔHRxn, based on the given standard heats of formation.
- Multiple Choice
Consider the following equation:
2 ClF3(g) + 2 NH3(g) → 1 N2(g) + 6 HF (g) + 6 Cl2(g)ΔHrxn = –1196 kJ
Determine the standard enthalpy of formation for chlorine trifluoride, ClF3.
- Multiple ChoiceFind ΔHrxn for the following reaction:
N2 + 2 O2 → 2 NO2
Based on the following data.
2 NO → N2 + O2 ΔH = −180 kJ
2 NO + O2 → 2 NO2 ΔH = −112 kJ - Multiple ChoiceIn which of the following is ΔH°rxn = ΔH°f at 1 atm and 298 K?
- Open Question
Calculate the enthalpy of the reaction 2NO(g) + O2(g) → 2NO2(g) given the following reactions and enthalpies of formation: 12N2(g) + O2(g) → NO2(g), δH∘a=33.2 kJ 12N2(g) + 12O2(g) → NO(g), δH∘b=90.2 kJ
- Open Question
What is the isobaric heat of combustion for ethane, C2H6(g), in kJ per mole of ethane at 298.15 k?
- Open Question
How much energy is required to decompose 765 g of PCl3
- Open Question
What is the heat of combustion of ethane, C2H6, in kilojoules per mole of ethane? Enthalpy of formation values can be found in this list of thermodynamic properties.
- Open Question
Use standard enthalpies of formation to calculate δh∘rxn for the following reaction: 2 H2S(g) + 3 O2(g)→ 2 H2O(l) + 2SO2(g)
- Open Question
Calculate the enthalpy of the reaction 2NO(g) + O2(g) → 2NO2(g)
- Open QuestionFor which one of the following is the enthalpy of the reaction the same as the enthalpy of formation?
- Open QuestionUse the molar bond enthalpy data in the table to estimate the value of δ𝐻∘rxn for the equation
- Open QuestionFor which one of the following reactions is δh°rxn equal to the heat of formation of the product?