A sample of an ideal gas is stored at 21 degrees Celsius. To what temperature would it have to be heated to double the volume of the gas?
Doubling the Kelvin temperature will double the volume of an ideal gas. In Celsius, this means the temperature would have to be increased to 315°.
The answer is based on the idea that the volume of a gas is directly proportional to its temperature (that is, if you double the temperature, the volume will be doubled as a result). However, for this to be true, the temperature must be in the Kelvin scale.
To convert Celsius to Kelvin, you simply add 273 to the Celsius reading. So, 21°C becomes 294 K.
If you double the Kelvin temperature, it becomes 588 K. Convert this to Celsius, and the result is 315°C.