A sealed, rigid glass bulb contains an ideal gas at an initial temperature of 325 K.…
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A sealed, rigid glass bulb contains an ideal gas at an initial temperature of 325 K. The gas cannot escape, and the volume of the bulb remains fixed throughout the experiment. The bulb is slowly cooled in an ice–salt bath until the gas reaches a final temperature of 255 K.
(a) Predict qualitatively whether the pressure of the gas at 255 K is greater than, less than, or equal to its pressure at 325 K.
(b) Using the postulates of the kinetic-molecular theory, explain the microscopic reasons for the pressure change you predicted in part (a). Your explanation should explicitly reference particle speed and frequency of wall collisions.
(c) State one assumption about the amount of gas present that is necessary for the reasoning in part (b) to be valid.