CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
The figure below is not provided. Instead, answer the questions using a verbal description:
"A Maxwell–Boltzmann speed distribution for nitrogen gas at 300 K has its peak (most probable speed) at approximately 420 m s⁻¹. A second curve for 900 K is broader and shifted to higher speeds, with its peak at approximately 740 m s⁻¹."
(a) Using complete sentences, describe two key differences between the 300 K and 900 K distributions in terms of their shapes and positions along the speed axis.
(b) Explain why the area under each curve is identical even though the curves have different shapes.
(c) Predict how the fraction of nitrogen molecules possessing speeds greater than 1 000 m s⁻¹ compares at the two temperatures. Justify your answer without performing numerical integration.
(d) A sample of neon gas is brought to 300 K. Sketch qualitatively (no numerical axes needed) how the speed distribution of neon at 300 K would compare with that of nitrogen at the same temperature. Explain the physical basis for the similarities or differences you indicate.