A sample of methane gas is at 1.50 atm and 305 K. The sample is put in a freezer and cooled to 255 K at constant volume. What is the new pressure?

Answer 1

We are given an initial pressure (1.50 atm) and temperature (305K). We are also given a final temperature of 255K and asked for the final pressure. In this case where the volume is constant, we have Gay Lussac's Law.

P1 / T1 = P2 / T2

1.50 atm / 305K = P2 / 255K

P2 = 1.25 atm