Calculate the enthalpy of formation of benzene from the following data.2C6H6(g) + 15O2(g) ---> 12CO2(g) + 6H2O(l)    ΔHc° = -6631.54 kJ mol-1ΔfH°(CO2, g) = -393.18 kJ mol-1ΔfH°(H2O, l) = -284.47 kJ mol-1(Note, ΔfH° is the symbol for enthalpy of formation.)Provide answer as KJ mol-1

The octane number of gasoline is based on a comparison of the gasolines behavior with that of 2,2,4-trimethylpentane, C8H18(), which is arbitrarily assigned an octane number of 100. The standard enthalpy of combustion of this compound is 5456.6 kJ/mol. (a) Write the thermochemical equation for the combustion of 2,2,4-trimethylpentane. (b) Use the standard enthalpies of formation in Appendix G to calculate the standard enthalpy of formation of 2,2,4-trimethylpentane.

Write reactions for which the enthalpy change will be a. Hf for solid aluminum oxide. b. the standard enthalpy of combustion of liquid ethanol, C2H5OH(l). c. the standard enthalpy of neutralization of sodium hydroxide solution by hydrochloric acid. d. Hf for gaseous vinyl chloride, C2H3Cl(g). e. the enthalpy of combustion of liquid benzene, C6H6(l). f. the enthalpy of solution of solid ammonium bromide.

When 1.000 g of ethylene glycol, C2H6O2, is burned at 25C and 1.00 atmosphere pressure, H2O(l) and CO2(g) are formed with the evolution of 19.18 kJ of heat. a Calculate the molar enthalpy of formation of ethylene glycol. (It will be necessary to use data from Appendix C.) b Gf of ethylene glycol is 322.5 kJ/mol. What is G for the combustion of 1 mol ethylene glycol? c What is S for the combustion of 1 mol ethylene glycol?

sample of natural gas is analyzed and found to be88.4% methane (CH4) and 11.6% ethane (C2H6) bymass. The standard enthalpy of combustion of methaneto gaseous carbon dioxide (CO2) and liquid water (H2O) is -891 kJ/mol. Write the equation for the combustionof gaseous ethane to carbon dioxide and water.Calculate the standard enthalpy of combustion of ethaneusing standard enthalpies of formation from Table R-11on page 975. Using that result and the standard enthalpyof combustion of methane in Table 15.3, calculate theenergy released by the combustion of 1 kg of natural gas.

When one mol of KOH is neutralized by sulfuric acid, q=56 kJ. (This is called the heat of neutralization.) At 23.7C, 25.0 mL of 0.475 M H2SO4 is neutralized by 0.613 M KOH in a coffee-cup calorimeter. Assume that the specific heat of all solutions is 4.18J/gC, that the density of all solutions is 1.00 g/mL, and that volumes are additive. (a) How many mL of KOH is required to neutralize H2SO4? (b) What is the final temperature of the solution?

The enthalpy of combustion of solid carbon to form carbon dioxide is 393.7 KJ/mol carbon, and the enthalpy of combustion of carbon monoxide to form carbon dioxide is 283.3 KJ/mol CO. Use these data to calculate H for the reaction 2C(s)+O2(g)2CO(g)

At 298 K, the standard enthalpies of formation for C2H2(g) and C6H6(l) are 227 kJ/mol and 49 kJ/mol, respectively. a. Calculate H for C6H6(l)3C2H2(g) b. Both acetylene (C2H2) and benzene (C6H6) can be used as fuels. Which compound would liberate more energy per gram when combusted in air?

A 21.3-mL sample of 0.977 M NaOH is mixed with 29.5 mL of 0.918 M HCl in a coffee-cup calorimeter (see Section 6.6 of your text for a description of a coffee-cup calorimeter). The enthalpy of the reaction, written with the lowest whole-number coefficients, is 55.8 kJ. Both solutions are at 19.6C prior to mixing and reacting. What is the final temperature of the reaction mixture? When solving this problem, assume that no heat is lost from the calorimeter to the surroundings, the density of all solutions is 1.00 g/mL, the specific heat of all solutions is the same as that of water, and volumes are additive.

A student performing a calorimetry experiment combined 100.0 ml. of 0.50 M HCI and 100.0 ml. of 0.50 M NaOH in a StyrofoamTM cup calorimeter. Both solutions were initially at 20.0 C, but when the two were mixed, the temperature rose to 23.2 C (a) Suppose the experiment is repeated in the same calorimeter but this time using 200 mL of 0.50 M HCl and 200.0 ml of 0.50 M NaOH. WIII the AT observed be greater than, less than, or equal to that in the first experiment, and why? (b) Suppose that the experiment is repeated once again in the same calorimeter, this time using 100 mL of 1.00 M HCI and 100.0 ml. of 1.00 M NaOH. Will the T observed be greater than, less than, or equal to that in the first experiment, and why?