Energy cycles in reactions

(i) Determine the enthalpy of combustion of pentane, in kJ mol$^{-1}$, using table 12 in the data booklet. $\ce{C5H12(g) + 8O2(g) -> 5CO2(g) + 6H2O(g)}$ (ii) Calculate the mass, in g, of carbon dioxide, $\ce{CO2}$, produced when 45.0 g of pentane react with…

Given the following data: $\ce{CaO(s) + CO2(g) -> CaCO3(s)}$ $\Delta H = -p\ \mathrm{kJ}$ $\ce{2Ca(s) + O2(g) -> 2CaO(s)}$ $\Delta H = -q\ \mathrm{kJ}$ $\ce{2CaCO3(s) -> 2Ca(s) + 2C(s) + 3O2(g)}$ $\Delta H = +r\ \mathrm{kJ}$ What is the $\Delta H$ of the…

Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, $\ce{CO}$, with bromine vapour, $\ce{Br2}$, started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model. (i) Write an…

Propene reacts with bromine to produce 1,2-dibromopropane. $\ce{CH3CH=CH2(g) + Br2(g) -> CH3CHBrCH2Br(g)}$ Calculate the enthalpy, in kJ, of the reaction using section 12 of the data booklet.

(i) Calculate the enthalpy change, $\Delta H$, for the overall synthesis of propyl ethanoate from propane and ethane shown above. Use section 12 of the data booklet. (ii) Two students each calculated the enthalpy change for the reaction between propan-1-ol and…

Determine the standard enthalpy change of the reaction, in kJ mol⁻¹. Use section 12 of the data booklet. Ignore interactions between ions and the solvent.

What is $\Delta H$, in kJ, in the energy cycle below? A. +20 - 165 B. +20 + 165 C. -20 + 165 D. -20 - 165

Which reaction has the lowest activation energy? A. $\ce{HBr(g) -> H(g) + Br(g)}$ B. $\ce{2Cl(g) -> Cl2(g)}$ C. $\ce{CH4(g) + Cl(g) -> CH3(g) + HCl(g)}$ D. $\ce{HBr(g) -> H+(g) + Br-(g)}$

Which radical is most likely to form when one covalent bond in bromochlorodifluoromethane, $\ce{CBrClF2}$, is broken by ultraviolet light in the upper atmosphere? A. •$\ce{CBrF2}$ B. •$\ce{CClF2}$ C. •$\ce{CBrClF}$ D. •$\ce{CBrClF2}$

In an oil refinery, nonadecane can be cracked into smaller molecules. Consider the reaction: $\ce{C19H40(g) -> 3C3H6(g) + C10H22(g)}$ Determine the standard enthalpy change, $\Delta H^\ominus$, for this reaction using section 12 of the data booklet.