Charles's law states that at constant pressure the volume of a fixed mass of gas is
- A. inversely proportional to the absolute temperature
- B. directly proportional to the absolute temperature
- C. independent of temperature
- D. proportional to the square of the temperature
Explanation
Volume rises in direct proportion to absolute temperature, so a graph of V against T in kelvin is a straight line that extrapolates back to the origin. Using degrees Celsius breaks the proportionality entirely, which is why the temperature must always be converted. This is the law behind a hot air balloon.