Combined and ideal Gas Laws Practice

Question

How do I determine the temperature in kelvin of 2.45 moles of gas contained in a 1.5 L canister at a pressure of 175 kPa?

Answer 1

The ideal gas law is

PV = nRT

By rearranging the formula to solve for temperature (T), we get:

T = PV/nR

Then for this particular set of values that becomes

T = (175 kPa x 1.5L) / (2.45 mol x 8.314 L kPa / mol K) = 12.89

meaning that the temperature of the gas here is about 12.89 K

Answer 2

You are given the following:

moles (n) = 2.45

volume (V) = 1.5 L

pressure (P) = 175 kPa

You are asked to find temperature (T) in degrees K

You can use the Ideal Gas Law: PV = nRT and solve for T

Before calculating, be sure that the units of R and P are in agreement. For example, if you use kPa for P then you want to use R = 8.314 L-kPa/Kmole. If you use atm for P, then you want to use R = 0.0821 Latm/Kmol.

Solving the Ideal Gas Law for T, you have T = PV/nR

T = (175 kPa)(1.5 L)/(2.45 moles)(8.314 LkPa/Kmol)

T = 12.9 K = 13 K