P/n=C
The pressure and the number of moles in a container are directly related. In a container where volume is held constant, an increase in the number of moles results in an increase in collisions and thus, an increase in pressure. Assume that there are 10 players on football field A and 200 on football field B running continuously in random directions. If fields A and B have the same area, the number of collisions between players in field A would be much less than that between the players in field B. If the players represent molecules of gas and the field the constant volume, the same scenario holds true. Thus a X1Y1=X2Y2 equation where three out of the four variables are known can be used to solve problems involving this relationship. For example, if it is known that a container holding 2 moles of oxygen gas had a pressure of 1.5 atm, you can easily find the number of moles that the same container can hold if the pressure was increased to 2 atm by setting up this proportion: 1.5atm/2 moles O2 = 2 atm/? mole O2. Using cross-multiplication, the answer should be around 2.7 moles.
Sample Questions:
1. Assuming all others are held constant. If a container held 1 mole of O2 at 1 atm, then how many moles will the container hold if the pressure is raised to 1.5 atm?
2. If a container which held one mole of methane gas at 3.4 atm. How many moles can the container hold if the pressure was 1.3 atm if all else remains constant?
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PV = C
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