Two moles of an ideal gas have an initial Kelvin temperature Ti and absolute pressure Pi. The gas undergoes a reversible isothermal compression from an initial volume Vi to a final volume 0.5Vi.
-Which one of the following expressions represents the final pressure of the gas?

Question

Quizplus · Accepted Answer

For an isothermal process, we know that PV = constant. Using this and the ideal gas law, we can write:
PiVi = nRTi
Pf(0.5Vi) = nRTi
where Pf is the final pressure, and n, R are constants for the given number of moles of gas and the ideal gas law constant, respectively.
Dividing the two equations, we get:
Pf = 2Pi
So, the final pressure is twice the initial pressure, which is given by choice C.

Two Moles of an Ideal Gas Have an Initial Kelvin