Given that 2.5 x 10^-2 moles of a hydrocarbon experience full combustion, resulting in the release of 104.1 kJ of heat, what is the molar enthalpy of combustion for said hydrocarbon?

A compound is 82.7% carbon and 17.3% hydrogen, and has a molar mass of approximately 60 g/mol. When 1.000 g of this compound burns in excess oxygen, the enthalpy change is 49.53 kJ. (a) What is the empirical formula of this compound? (b) What is the molecular formula of this compound? (c) What is the standard enthalpy of formation of this compound? (d) Two compounds that have this molecular formula appear in Appendix G. Which one was used in this exercise?

What mass of acetylene, C2H2(g), must be burned to produce 3420 kJ of heat, given that its enthalpy of combustion is 1301 kJ/mol? Compare this with the answer to Exercise 5.91 and determine which substance produces more heat per gram.

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

9.65 When 0.0157 g of a compound with a heat of combustion of —37.6 kJ/mol is burned in a calorimeter, 18.5 j of heat is released. What is the molar mass of the compound?

The combustion of 1.00 mol liquid methyl alcohol (CH3OH) in excess oxygen is exothermic, giving 727 kJ of heat. (a) Write the thermochemical equation for this reaction. (b) Calculate the enthalpy change that accompanies the burning 10.0 g methanol. (c) Compare this with the amount of heat produced by 10.0 g octane, C8H18, a component of gasoline (see Exercise 5.41).

Although the gas used in an oxyacetylene torch (Figure 5.7) is essentially pure acetylene, the heat produced by combustion of one mole of acetylene in such a torch is likely not equal to the enthalpy of combustion of acetylene listed in Table 5.2. Considering the conditions for which the tabulated data are reported, suggest an explanation.

In the process of isolating iron from its ores, carbon monoxide reacts with iron(III) oxide, as described by the following equation: Fe2O3(s)+3CO(g)2Fe(s)+3CO2(g)H=24.8kJ The enthalpy change for the combustion of carbon monoxide is 2CO(g)+O2(g)2CO2(g)H=566kJ Use this information to calculate the enthalpy change for the equation 4Fe(s)+3O2(g)2Fe2O3(s)H=?

The enthalpy change for the following reaction is 393.5 kJ. C(s,graphite)+O2(g)CO2(g) (a) Is energy released from or absorbed by the system in this reaction? (b) What quantities of reactants and products are assumed? (c) Predict the enthalpy change observed when 3.00 g carbon burns in an excess of oxygen.

The enthalpy change when 1 mol methane (CH4) is burned is 890 kJ. It takes 44.0 kJ to vaporize 1 mol water. What mass of methane must be burned to provide the heat needed to vaporize 1.00 g water?