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Ch.6 - Thermochemistry
Chapter 6, Problem 116

A gaseous fuel mixture stored at 745 mmHg and 298 K contains only methane (CH4) and propane (C3H8). When 11.7 L of this fuel mixture is burned, it produces 769 kJ of heat. What is the mole fraction of methane in the mixture? (Assume that the water produced by the combustion is in the gaseous state.)

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Ideal Gas Law

The Ideal Gas Law relates the pressure, volume, temperature, and number of moles of a gas through the equation PV = nRT. This law is essential for calculating the number of moles of gases in a mixture, which is necessary for determining the mole fraction of each component in the fuel mixture.
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Ideal Gas Law Formula

Mole Fraction

Mole fraction is a way of expressing the concentration of a component in a mixture, defined as the ratio of the number of moles of that component to the total number of moles of all components. It is crucial for understanding the composition of the fuel mixture and how it relates to the combustion process.
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Combustion Reaction

A combustion reaction involves the reaction of a fuel with oxygen to produce heat, carbon dioxide, and water. The heat produced during combustion can be quantified, and the stoichiometry of the reaction helps in determining the moles of reactants consumed, which is necessary for calculating the mole fraction of methane in the mixture.
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