Thermochemical Equations Answers

The enthalpy of formation for C6 H6 (I) is 49.0 kJ/mol. Consider the following reaction.Is the reaction endothermic or exothermic, and what is the enthalpy of reaction? Use .

Butane C4 H10 (g),(Hf = –125.6), combusts in the presence of oxygen to form CO2 (g) (Hf = –393.5 kJ/mol), and H2 O(g) (Hf = –241.82) in the reaction: What is the enthalpy of combustion, per mole, of butane? Use .

Nitrogen reacts with hydrogen to form ammonia according to the equation below.Standard Enthalpies of FormationSubstanceDHf (kJ/mol)C2 H2 (g)–26.7NH3 (g)–46.19HBr (g)236.23HCl (g)–92.30HF (g)–268.6HI (g)25.9NaCl (s)–411.0Based on the equation and the information in the table, what is the enthalpy of the reaction?

The enthalpies of formation of the compounds in the combustion of methane, ,are CH4 (g): Hf = –74.6 kJ/mol; CO2 (g): Hf = –393.5 kJ/mol; and H2 O(g): Hf = –241.82 kJ/mol.How much heat is released by the combustion of 2 mol of methane? Use .

Ammonia (NH3 (g), Hf = –45.9 kJ/mol ) reacts with oxygen to produce nitrogen and water (H2 O(g), Hf = –241.8 kJ/mol) according to the equation below.What is the enthalpy of the reaction? Use .

The Hrxn of formation of carbon dioxide is negative. Which statement is true?

Which statement is true if the Hrxn of a reaction is positive?

Manganese dioxide (MnO2(s), Hf = –520.0 kJ) reacts with aluminum to form aluminum oxide (AI2O3(s), Hf = –1699.8 kJ/mol) and manganese according to the equation below.What is the enthalpy of the reaction? Use .

Hydrogen ( H2 ) reacts with bromine ( Br2 ) to produce hydrogen bromide (HBr) gas as shown in the equation below.Standard Enthalpies of FormationSubstanceDHf (kJ/mol)Br2 (l)0.0Br2 (g)30.907HBr (g)–36.4HCl (g)–92.307HI (g)26.48H2 (g)0.0I2 (g)62.438Based on the equation and the information in the table, what is the enthalpy of the reaction?

Sulfur reacts with oxygen to form sulfur dioxide (SO2(g), Hf = –296.8 kJ/mol) according to the equation below.What is the enthalpy change for the reaction? Use .