A rigid, sealed 1.00 L steel cylinder contains argon gas at an initial temperature of…
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A rigid, sealed 1.00 L steel cylinder contains argon gas at an initial temperature of 300 K and an initial pressure of 1.20 atm. The cylinder is slowly warmed in a water bath until the final gas temperature reaches 450 K. Throughout the process, no gas escapes and the volume of the cylinder is constant.
Respond to the following prompts. Answer all parts for full credit.
(a) Describe, in terms of the motion and kinetic energies of individual argon atoms, how the Maxwell–Boltzmann distribution of speeds in the gas changes as the temperature rises from 300 K to 450 K.
(b) Explain why the macroscopic pressure exerted by the gas on the walls of the cylinder increases as the temperature rises, even though the amount of gas and the volume remain constant.
(c) Using proportional reasoning and any relevant relationships among temperature, average kinetic energy, and molecular speed, determine the factor by which the root-mean-square (rms) speed of the argon atoms changes between 300 K and 450 K.
(d) Using your result from part (c), calculate the final pressure of the gas in the cylinder after it reaches 450 K. Express the answer with appropriate units.