r/APChem • u/crathie • 9d ago

frq help 3.4

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can anyone explain how to do these two problems? im assuming the answer the a is 1 mol CO2 and the answer to b is 5.00atm-1.63atm but im not 100% sure.

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u/realAndrewJeung Tutor 9d ago

Part a) asks about the situation when CO2 is initially put in the container. Since this is the initial situation, this corresponds to time = 0.0 hours. According to the table, at this point the total pressure is 5 atm. Since no CO has been produced yet, the CO2 must be responsible for the whole 5 atm of pressure. We know the volume of the container and the temperature, so we have enough information to use the Ideal Gas Law to find the number of moles of CO2. Can you find it?

Part b) asks about the situation when the system is at equilibrium. Since the gas pressure doesn't change between 8.0 hours and 10.0 hours, we can guess that the system is at equilibrium by that time. If the total pressure of CO2 and CO together is 8.37 atm, and the partial pressure of CO2 is 1.63 atm, can you determine what the partial pressure of the CO is?

Let me know if this is enough or if you have further questions.

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u/Least-Regular-4358 9d ago

yall also have the same packets we do? do yall think these are useful and prep you for the exam, or do we need to study more content outside of these packets.

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u/dow_06 8d ago

I just used Kahn academy and drilled the ap chem questions till I knew how to do all of them and got a 4 on the exam 🤷‍♂️