You have 0.5 L of air at 203 k in an expendable container at constant pressure. You heat the container to 273 k. What is the volume of air?

Charles law states that for a fixed mass of gas at constant pressure the volume of the gas is directly proportional to the temperature in Kelvin scale

v1/T1 = v2/T2

Where v1 is volume and T1 is temperature at the first instance

v2 is volume and T2 is temperature at the second instance

Substituting the values in the equation

0.5 L / 203 K = v2 / 273 K

v2 = 0.672 L

The volume of Air after heating is 0.672 L