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Ch.6 - Thermochemistry
Tro - Chemistry: A Molecular Approach 4th Edition
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Tutti i libri di testoTro 4th EditionCh.6 - ThermochemistryProblema 93a
Capitolo 6, Problema 93a

Determine the mass of CO2 produced by burning enough of each fuel to produce 1.00×102 kJ of heat. a. CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) ΔH°rxn = –802.3 kJ

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Identify the given reaction: CH4(g) + 2 O2(g) -> CO2(g) + 2 H2O(g) with ΔH°rxn = -802.3 kJ.
Understand that the reaction releases 802.3 kJ of heat per mole of CH4 burned.
Calculate the moles of CH4 needed to produce 1.00 * 10^2 kJ of heat using the ratio: (1 mole CH4 / 802.3 kJ) * 100 kJ.
Use the stoichiometry of the reaction to determine the moles of CO2 produced, which is a 1:1 ratio with CH4.
Convert the moles of CO2 to mass using the molar mass of CO2 (44.01 g/mol).

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Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on the balanced chemical equation. It allows us to determine the amount of product formed or reactant consumed when a specific quantity of another substance is involved. In this case, it will help us calculate the mass of CO2 produced from the combustion of CH4 by using the given enthalpy change and the molar ratios from the reaction.
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Stoichiometry Concept

Enthalpy Change (ΔH)

Enthalpy change (ΔH) is a measure of the heat energy absorbed or released during a chemical reaction at constant pressure. A negative ΔH indicates that the reaction is exothermic, meaning it releases heat. In this question, the ΔH of -802.3 kJ for the combustion of methane (CH4) indicates that burning one mole of CH4 releases this amount of energy, which is crucial for determining how much CO2 is produced for a specific heat output.
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Enthalpy of Formation

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is essential for converting between the mass of a substance and the number of moles. In this problem, knowing the molar mass of CO2 will allow us to convert the moles of CO2 produced from the stoichiometric calculations into grams, providing the final answer for the mass of CO2 generated from the combustion of methane.
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Molar Mass Concept
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