Calculate Δ S and Δ Gf° for the combustion of ethane (C2H6). Refer to the values in the picture.

A 1.27-g sample of fumaric acid (C4H4O4) is burned in a bomb calorimeter and the temperature increases from 24.70 °C to 27.50 °C. The calorimeter contains 1.01×103 g of water and the bomb has a heat capacity of 755 J/°C. Based on this experiment, calculate ΔE for the combustion reaction per mole of fumaric acid burned (kJ/mol).

The ΔH°rxn for the following reaction: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) is –55.7 kJ/mol. Given the following enthalpies of formation, determine ΔH°f of H2O(l). ΔH°f NaOH(aq) = −470.1 kJ/mol ΔH°f HCl(aq) =  −167.2 kJ/mol ΔH°f NaCl(aq) =  −407.2 kJ/mol

also, Change in Gibbs Free energy Reaction Spontaneity

Does a negative  ΔHᵣₓₙ mean that the heat of reaction can be thought of as a reactant or as a product?

Calculate the change in internal energy (ΔE) for a system that is giving off 3.0 kcal of heat and is changing from 1.00 L to 8.00 L in volume at a pressure of 2.00 atm. (Remember that 101.3 J = 1 L∙atm; 1 cal = 4.18 J)

Calculate ΔH° for the reaction shown below using standard enthalpy of formation values. KCl (s)   →   K+1 (aq)   +   Cl-1 (aq) Be sure to include a unit with your answer.