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Ch.6 - Gases
Tro - Chemistry: A Molecular Approach 6th Edition
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217Not the one you use?Change textbook
All textbooksTro 6th EditionCh.6 - GasesProblem 127
Chapter 6, Problem 127

A catalytic converter in an automobile uses a palladium or platinum catalyst (a substance that increases the rate of a reaction without being consumed by the reaction) to convert carbon monoxide gas to carbon dioxide according to the reaction: 2 CO(g) + O2(g) → 2 CO2(g) A chemist researching the effectiveness of a new catalyst combines a 2.0:1.0 mole ratio mixture of carbon monoxide and oxygen gas (respectively) over the catalyst in a 2.45-L flask at a total pressure of 745 torr and a temperature of 552 °C. When the reaction is complete, the pressure in the flask has dropped to 552 torr. What percentage of the carbon monoxide was converted to carbon dioxide?

Verified step by step guidance
1
Convert the given temperature from Celsius to Kelvin by adding 273.15 to the Celsius temperature.
Use the ideal gas law, PV = nRT, to calculate the initial moles of gas in the flask. Remember to convert pressure from torr to atm by dividing by 760.
Determine the initial moles of CO and O2 using the given mole ratio (2.0:1.0) and the total initial moles calculated from the ideal gas law.
Calculate the change in moles of gas using the initial and final pressures, again using the ideal gas law to find the final moles of gas.
Use stoichiometry to determine the moles of CO converted to CO2, and then calculate the percentage of CO converted by comparing the moles of CO converted to the initial moles of CO.

Key Concepts

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

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on the balanced chemical equation. It allows chemists to determine the proportions of substances involved in a reaction. In this case, the stoichiometric coefficients indicate that two moles of carbon monoxide react with one mole of oxygen to produce two moles of carbon dioxide, which is essential for calculating the conversion percentage.
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Stoichiometry Concept

Gas Laws

Gas laws describe the behavior of gases in relation to pressure, volume, and temperature. The ideal gas law (PV=nRT) is particularly useful for understanding how changes in these variables affect gas reactions. In this scenario, the initial and final pressures, along with the volume and temperature, can be used to determine the amount of gas present before and after the reaction, which is crucial for calculating the conversion of carbon monoxide.
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Catalysis

Catalysis refers to the process of increasing the rate of a chemical reaction by adding a substance called a catalyst, which is not consumed in the reaction. In the context of the catalytic converter, palladium or platinum facilitates the conversion of harmful gases like carbon monoxide into less harmful gases like carbon dioxide. Understanding how catalysts work helps in evaluating the efficiency of the reaction and the extent of conversion achieved.
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Related Practice
Textbook Question

A mixture of 8.0 g CH4 and 8.0 g Xe is placed in a container and the total pressure is found to be 0.44 atm. Determine the partial pressure of CH4.

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Textbook Question

A mixture of CO(g) and O2(g) in a 1.0-L container at 1.0×103 K has a total pressure of 2.2 atm. After some time, the total pressure falls to 1.9 atm as the result of the formation of CO2. Determine the mass (in grams) of CO2 that forms.

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Textbook Question

An 11.5-mL sample of liquid butane (density = 0.573 g/mL) is evaporated in an otherwise empty container at a temperature of 28.5 °C. The pressure in the container following evaporation is 892 torr. What is the volume of the container?

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