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A sample of a gas has a pressure of 920 mmHg and a volume of 250 mL. If the volu

ID: 1055724 • Letter: A

Question

A sample of a gas has a pressure of 920 mmHg and a volume of 250 mL. If the volume is increased to 1.5 liters, what will the new pressure be? Show your calculations. Barney measures the car tire pressure on his P T Cruiser one afternoon when it is 59.0 degrees Fahrenheit (15.0 degrees Celsius) and finds it to be 3J PSI The next morning, it is 23.0 degrees Fahrenheit (-5.0 degrees Celsius), what would the pressure be at that time of the morning? Show your calculations. Explain why the pressure of a gas changes as temperature changes. What is going on at the molecular level in terms of molecular motion and collisions?

Explanation / Answer

1. using,

P1V1 = P2V2

with,

P1 and V1 be initial pressure and volume

P2 and V2 be final pressure and volume

we get,

final pressure P2 = 920 x 0.250/1.5 = 153.333 mmHg

2. using,

P1/T1 = P2/T2

with,

P1 and T1 be initial pressure and temperature

P2 and T2 be final pressure and temperature

we get,

final pressure P2 = 33 x 23/59 = 12.864 PSI

3. As the temperature increases, the molecular motion of gases increases, which exerts a greater force on the walls of the container. Thereby the pressure of the system increases.