Assume that you have a sample of gas in a cylinder with a moveable piston,as shown in diagram (1).The initial pressure,number of moles,and temperature of the gas are noted on the diagram.Which diagram (2)-(4)most closely represents the result of doubling the number of moles of gas while keeping the pressure and temperature constant?
A)diagram (2)
B)diagram (3)
C)diagram (4)

Question

Assume that you have a sample of gas in a cylinder with a moveable piston,as shown in diagram (1).The initial pressure,number of moles,and temperature of the gas are noted on the diagram.Which diagram (2)-(4)most closely represents the result of doubling the number of moles of gas while keeping the pressure and temperature constant? 
A)diagram (2) 
B)diagram (3) 
C)diagram (4)

Quizplus · Accepted Answer

According to the ideal gas law, PV = nRT, when pressure and temperature are constant, increasing the number of moles of gas will result in an increase in volume. Therefore, the best representation of doubling the number of moles while keeping the pressure and temperature constant would be diagram (3) where the volume of the gas has increased. Diagram (2) shows a decrease in volume, which would only happen if pressure and temperature were decreased. Diagram (4) shows an increase in both pressure and volume, which would only happen if temperature were increased.

Assume That You Have a Sample of Gas in a Cylinder