Thermochemical Equations Answers

Which statement about Hf is true?

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 .

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 .

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 .

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?

Hydrogen reacts with chlorine to form hydrogen chloride (HCl (g), Hf = –92.3 kJ/mol) according to the reaction below.Which statement is correct? Use .

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 .

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

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 .

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?