speed. The rms speed of the more massive Ar molecules is considerably less a t the same temperature, because rms speed is inversely proportional to mass. However, the average kinetic energy of both kinds of atoms a t the same temperature is the same, because temperature is a measure of the kinetic energy of the atoms or molecules of a gaseous substance.
Constant V Constant n Constant P Constant T
(a) The speed of each He atom at 27 "C is 926 mls. True
False
(h) The rms speed ofAr atoms at 27 "Cis the same as the rms speed of He abms at 27 "C. True False (el The average kinetic energy of Ar atoms at 27 "C is the same as the average kinetic energy of He atoms at 27 "C. True False
Solution The root mean square speed of He is 926 mls a t 27 "C, but this does not mean that each and every He atom has this
716
Journal of Chemical Education
Summary The quiz can be completed by general chemistry students in about 10 min. The grades are often surprising. Students who score well on the more "traditional" type of quiz often are outperformed by their less mathematically inclined classmates. The auiz solutions orovide a eood starting point for further di'scussion of theLKineticTh&& of Gases. and stndents'misconce~tionsare cleared no uoon closer examination of incorrect responses.
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Literature Cited 1. Nakhleh, M.
B. ; Mitchell. R. C. J
Chem. Edur 1993.70.190-192.
