A scientist measures the standard enthalpy change for the following reaction to be -876.3 kJ: 2NH3(g) + 3 N2O(g) 4N2(g) +3 H20(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of NH3(g) is kJ/mol.

Compounds with carboncarbon double bonds, such as ethylene, C2H4, add hydrogen in a reaction called hydrogenation. C2H4(g)+H2(g)C2H6(g) Calculate the enthalpy change for this reaction, using the following combustion data: C2H4(g)+3O2(g)2CO2(g)+2H2O(l);H=1411kJC2H6(g)+72O2(g)2CO2(g)+3H2O(l);H=1560kJH2(g)+12O2(g)H2O(l);H=286kJ

When 2.50 g of methane burns in oxygen, 125 kJ of heat is produced. What is the enthalpy of combustion per mole of methane under these conditions?

Using the data in Appendix G, calculate the standard enthalpy change for each of the following reactions: (a) Si(s)+2F2(g)SiF4(g) (b) 2C(s)+2H2(g)+O2(g)CH3CO2H(l) (c) CH4(g)+N2(g)HCN(g)+NH3(g) ; (d) CS2(g)+3Cl2(g)CCl4(g)+S2Cl2(g)

Given the following (hypothetical) thermochemical equations: A+B2C;H=447kJA+3D2E;H=484kJ2D+B2F;H=429kJ Calculate H, in kJ, for the equation 4E+5B4C+6F

Which of the enthalpies of combustion in Table 5.2 the table are also standard enthalpies of formation?

In a calorimetric experiment, 6.48 g of lithium hydroxide, LiOH, was dissolved in water. The temperature of the calorimeter rose from 25.00C to 36.66C. What is H for the solution process? LiOH(s)Li(aq)+OH(aq) The heat capacity of the calorimeter and its contents is 547 J/C.

In a bomb calorimeter, the reaction vessel is surrounded by water that must be added for each experiment. Since the amount of water is not constant from experiment to experiment, the mass of water must be measured in each case. The heat capacity of the calorimeter is broken down into two parts: the water and the calorimeter components. If a calorimeter contains 1.00 kg water and has a total heat capacity of 10.84 kJ/C, what is the heat capacity of the calorimeter components?

How much heat is absorbed by a 44.7-g piece of leadwhen its temperature increases by 65.4°C?

9.41 Under what conditions does the enthalpy change equal the heat of a process?