Uploaded March 2021 | Updated September 2026, 1 hour ago
An experiment to demonstrate Charles' Law - the behaviour of a gas when heated at constant pressure.
The experiment features a glass capillary tube that is sealed at one end and has a mercury thread at the other, which is able to move along the tube when the gas expands.
The tube is heated in a water bath: A scale allows the volume of the gas to be measured and a thermometer shows the temperature in celsius.
Apologies for the shaky camera work. The video was taken in time lapse (actual time for the experiment was around 30 minutes) and it was necessary to move the camera to give clear shots of the mercury thread and thermometer.
Some of you may want to think about two sources of error: Parallax and the fact that some of the gas column sticks out above the water line. Despite these sources of error, I found that the data from the experiment have a pretty good measurement of absolute zero.
An experiment to demonstrate Charles' Law - the behaviour of a gas when heated at constant pressure.
The experiment features a glass capillary tube that is sealed at one end and has a mercury thread at the other, which is able to move along the tube when the gas expands.
The tube is heated in a water bath: A scale allows the volume of the gas to be measured and a thermometer shows the temperature in celsius.
Apologies for the shaky camera work. The video was taken in time lapse (actual time for the experiment was around 30 minutes) and it was necessary to move the camera to give clear shots of the mercury thread and thermometer.
Some of you may want to think about two sources of error: Parallax and the fact that some of the gas column sticks out above the water line. Despite these sources of error, I found that the data from the experiment have a pretty good measurement of absolute zero.
