Continue this process until data is obtained at at least five different temperatures.įor each pair of volume-temperature values, enter the data in the table. Then measure the height of the column of gas and calculate the volume of the gas. Carefully adjust the amount of mercury in the manometer so that the heights of the two columns of mercury are identical. (This is admittedly a somewhat fanciful way to alter the temperature.) The volume of the gas will change in response to the temperature change.
Read the temperature from the thermometer, enter the temperature and volume in the boxes provided, and plot the point on the graph.Ĭhange the temperature of the system by dragging the liquid in the thermometer to a higher or lower level. The inside diameter of the manometer tube is 4.286 cm.
(The air has been given an artificial light green color to illustrate its presence.) The amount of mercury in the manometer has been adjusted so that the two columns of mercury have the same height, and thus the pressure of the gas equals the atmospheric pressure.Ĭarefully measure the height of the column of trapped air and determine the volume of the trapped gas. Determine how the volume of a gas changes with the temperature for a fixed amount of gas and pressure.Ī sample of air is now trapped in the closed end of the manometer.
This temperature is called absolute zero. If a decrease in temperature results in a decrease in volume, what happens if the temperature is lowered to a point where the volume drops to zero? A negative volume is obviously impossible, so the temperature at which the volume drops to zero must, in some sense, be the lowest temperature that can be achieved. Is this relationship linear? A plot of V vs T can be used to test this hypothesis. Intuitively, it is expected that the volume of the gas will increase as the temperature increases. The pressure was held constant by adjusting the height of mercury so that the two columns of mercury had equal height, and thus the pressure was always equal to the atmospheric pressure. This tube was immersed in a water bath by changing the temperature of the water, Charles was able to change the temperature of the gas. A quantity of gas was trapped in a J-shaped glass tube that was sealed at one end. The equipment used by Jacques Charles was very similar to that employed by Robert Boyle. Just as Robert Boyle made efforts to keep all properties of the gas constant except for the pressure and volume, so Jacques Charles took care to keep all properties of the gas constant except for temperature and volume. Given the interest in hot air balloon at that time, it is easy to understand why these men should be interested in the temperature-volume relationship for a gas. Two of the prominent french scientists, Jacques Charles and Joseph-Louis Gay-Lussac, made detailed measurements on how the volume of a gas was affected by the temperature of the gas. Hot air balloons were extremely popular at that time and scientists were eager to improve the performance of their balloons. The next significant advance in the study of gases came in the early 1800's in France.
Gas Laws: Charles's Law Gas Laws Charles's Law Concepts