The ΔrH for the oxidation of solid sulfur to SO3 is -396  kJmol−1 and for the oxidation of SO2 to SO3 is -98.9  kJmol−1 . Find the enthalpy of formation of SO2 under these conditions.

Determine the heat involved in the combustion of liquid hydrazine by using the following reactions. 2NH3(g) + 3N2O(g) → 4N2(g) + 3H2O(ℓ)      ΔH°= –1013 kJ/molN2O(g) + 3H2(g) → N2H4(ℓ) + H2O(ℓ)      ΔH°= –317 kJ/mol2NH3(g) + ½O2(g) → N2H4(ℓ) + H2O(ℓ)      ΔH°= –142.9 kJ/molH2(g) + ½ O2(g) → H2O(ℓ)       ΔH°= –285.8 kJ/mol Then, Launching a small spacecraft to study Jupiter required approximately 28 million kJ. Assume that hydrazine was the only fuel. What mass of hydrazine, in kilograms, was needed for the launch?

Copper has been used for thousands of years, either as a pure metal or in alloys. It is frequently used today in the production of wires and cables. Copper can be obtained through smelting or recycling. Determine the energy associated with each of these processes in order to recycle 1.40 mol Cu. The smelting of copper occurs by the balanced chemical equation: CuO(s) +CO(g) → Cu(s) +CO,(g) where AHtCuo is = - 155 kJ/mol. Assume the process of recycling copper is simplified to just the melting of the solid Cu starting at 25°C. The melting point of Cu is 1084.5°C with AH®fus = 13.0 kJ/mol and a molar heat capacity, CPCU = 24.5 J/mol:°C.

Given the overall reaction from the previous problem: 2 CO (g) + 6 H2 (g) D 2 CH4 (g) + 2 H2O (g) Using Le Chatelier’s principle, predict which direction the reaction will shift to reestablish equilibrium for each of the following changes: Calculate the enthalpy of reaction for this reaction using the standard thermodynamics values for the reactants and products. Is the reaction endothermic or exothermic? Now, use Le Chatelier’s principle again to determine the direction the equilibrium will shift if heat is added to the reaction.  If 35 kPa of CO is mixed with 35 kPa of hydrogen in a 1.5 L container at 25°C, what is the theoretical yield of methane?

A 3.000 g sample of food was then burned in a calorimeter to determine its Calories per gram content. 50mL of water were used to determine ΔT of the reaction. Initial temperature of the water at the start of the combustion reaction was 20oC, final temperature was 99oC. Calorimeter constant for this calorimeter is 10.0J/oC. How much heat has been absorbed by the water sample?

When a 7.00 g sample of KSCN is dissolved in water in a calorimeter that has a total heat capacity of 5.28 kJ⋅K^-1, the temperature decreases by 0.330 K Calculate the molar heat of solution of KSCN.

Calculate the enthalpy change for the reaction C2H2(g) + 2H2(g) → C2H6(g)     ΔrH = ? from the following information: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)    ΔrH = –2320 kJ/mol2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g)    ΔrH = –3040 kJ/mol2H2(g) + O2(g) → 2H2O(g)                         ΔrH = –572 kJ/mol

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 195.kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 69.kJ of work is done on the mixture during the reaction.  Calculate the change in energy of the gas mixture during the reaction. Be sure your answer has the correct number of significant digits. Is the reaction exothermic or endothermic?

Calculate the standard enthalpy change for the reaction at 25 ∘C. Standard enthalpy of formation values can be found in this list of thermodynamic properties. 2CH3OH(g)+3O2(g)----> 2CO2(g)+4H2O(g)

Calculate the enthalpy of decomposing hydrogen iodide to produce hydrogen and iodine.                                          2HI(g) →  I2(s) + H2(g)   I2(s) → I2(g)                                  ΔH⁰ = 124.8 kJ/mol I2(g) + H2(g) → 2HI(g)                          ΔH⁰ = - 73.0 kJ/mol