When air increases in temperature, the air inside a jar will try to expand. If the jar could expand like a balloon to keep pressure the same , then the gas volume will increase. In this case, 0.24 calories will be needed to increase the temperature of 1 gram of air by 1 degree Celsius. Warm air will rise and cold air will descend, so that mixing occurs. This makes it difficult to estimate actual energy changes.
Warm air is associated with lower pressure, since warm air tends to expand and move upward.
Cold air is associated with high pressure because it tends to be heavy and move downward due to gravity. For each gram, air provides 4-5 times more degrees Celsius temperature change than water for each calorie invested. The difficulty with air is that it is harder to contain in a jar. As temperature increases, the air will increase pressure and try to expand. If some of the air escapes from the jar, we will get incorrect results.