A gas occupies 300 cm3 at 27 degrees Celsius. At constant pressure, what volume will it occupy at 127 degrees Celsius?

Explanation

Converting to kelvin gives 300 K and 400 K, and the volume scales in the same ratio, so 300 multiplied by 400 divided by 300 gives 400 cm3. Using Celsius directly would give the wrong ratio of 127 over 27 and the absurd second option. Absolute temperature is non negotiable in every gas law calculation.