CHEM 177 SI 11/18/2015TINA AKINYI

Chapter 10.2-10.10.7

  1. Ar and He are both gases atroomtemperature. How dotheaveragemolecularvelocities(V) of theiratomscompare at this temperature?

(A) VAr= 10VHe (B) VHe=3VAr(C) VAr= 3VHe

  1. A sample of a volatile liquid is introduced to anevacuatedcontainerwitha movablepiston.Whichchange occurs as the piston is raised?(Assumesomeliquidremains.)

i)Thefraction of themoleculesinthegasphaseincreases

ii)The pressure in the container decreases

(A) I only (B) II only(C) Both I and II(D) NeitherI nor II

3. Compounds of uranium-235 and uranium-238 can beseparated fromone another by

(A) / Distillation.
(B) / Effusion.
(C) / Fractionalcrystallization.
(D) / Paperchromatography.

4. The average molecularvelocity ina gas sample at 300 Kis 500 m/s. The temperature ofthis gas is increased untilthe average velocity of itsmoleculesis 1000 m/s. What isthe new temperature?

(A) 420 K (B) 573 K(C) 600 K(D) 1200K

5. Twosamplesofgas,oneofargonandoneofhelium,havethesamepressure,temperature andvolume. Whichstatementistrueassumingbothgasesbehaveideally?

(A)Theheliumsamplecontainsmoreatomsthantheargonsampleandthe heliumatomshaveahigheraveragespeed.
(B) Thetwosampleshavethesamenumberofatomsbuttheheliumatomshaveahigheraveragespeed.
(C) Thetwosampleshavethesamenumberofatomsandbothtypesofatomshavethesameaveragespeed.
(D) Thetwosampleshavethesamenumberofatomsbuttheargonatomshaveahigheraveragespeed.

6. 5.600 g of solid CO2 is put in an empty sealed 4.00 L container at a temperature of 300 K. When all the solid CO2 becomes gas, what will be the pressure in the container? Assume the temperature is constant, and the volume of the container doesn’t change.