MT 3
Spring 2016
Chem 305
1) Which description best fits a gas?
A) definite shape and volume; strong intermolecular attractions
B) definite volume; shape of container; moderate intermolecular attractions
C) definite volume; shape of container; weak intermolecular attractions
D) volume and shape of container; no intermolecular attractions
E) volume and shape of container; strong intermolecular attractions
2) Which transformation is evaporation?
A) liquid → solid B) liquid → gas C) solid → liquid D) solid → gas
3) Which process is exothermic?
A) gas → liquid B) liquid → gas C) solid → liquid D) solid → gas
4) The number of mm Hg in one atmosphere is ________.
A) 14.7 B) 760 C) 1.00 D) 29.9
5) Which of the assumptions of the kinetic-molecular theory best explains the observation that a
gas can be compressed?
A) Gas molecules move at random with no attractive forces between them.
B) The velocity of gas molecules is proportional to their Kelvin temperature.
C) The amount of space occupied by a gas is much greater than the space occupied by the actual
gas molecules.
D) In collisions with the walls of the container or with other molecules, energy is conserved.
6) What would be the new pressure if a 400 mL gas sample at 380 mm Hg is expanded to 800
mL with no change in temperature?
A) 190 mm Hg B) 380 mm Hg C) 570 mm Hg D) 760 mm Hg
7) A sample of gas has a volume of 135 mL at 0.600 atm. What would be the volume if the
pressure is decreased to 0.200 atm while temperature is held constant?
A) 45.0 mL B) 101 mL C) 135 mL D) 405 mL
8) A sealed container with gas at 2.00 atm is heated from 20.0 K to 40.0 K. The new pressure is
A) 0.500 atm. B) 1.00 atm. C) 4.00 atm. D) 2.14 atm. E) 1.87 atm.
9) How will the volume of a fixed sample of gas change if the pressure is doubled and its Celsius
temperature is halved?
A) The change cannot be determined without more specific information.
B) It will double.
C) It will decrease by a factor of 4.
D) It will decrease by a factor of 2.
10) Which of the following is the definition of standard temperature and pressure?
A) 273°C and 760 torr B) 273 K and 655 mm Hg
C) 273 K and 760 mm Hg D) 0 K and 1 atm
11) How many moles of gas are present in a 10.0 liter sample at STP?
A) 224 moles B) 22.4 moles C) 10.0 moles D) 0.446 moles
12) Consider a sample of helium and a sample of neon, both at 30.0°C and 1.5 atm. Both
samples have a volume of 5.0 liters. Which statement concerning these samples is not true?
A) Each sample contains the same number of atoms of gas.
B) Each sample weighs the same amount.
C) Each sample contains the same number of moles of gas.
D) The density of the neon is greater than the density of the helium.
13) How many grams of O2 are contained in a 25.0 L sample at 5.20 atm and 28.0°C?
A) 1810 g B) 168 g C) 84.2 g D) 5.26 g
14) A sample of CO2 gas at 100.°C has a volume of 250. mL at 760. mm Hg. How many moles
of CO2 are present?
A) 0.00816 mol B) 0.0304 mol C) 6.20 mol D) 8.16 mol
15) A mixture of the gases N2, O2, and He has a total pressure of 760 mm Hg. If the partial
pressure of N2 is 90 mm Hg and of O2 is 270 mm Hg, What is the partial pressure of He?
A) 1120 mm Hg B) 760 mm Hg C) 400 mm Hg D) 360 mm Hg
16) Which molecule will undergo only London dispersion forces when interacting with other
molecules of the same kind?
A) HF B) CH2Cl2 C) C4H10 D) NaC2H3O2
17) As the temperature of a liquid is lowered, what happens to its vapor pressure?
A) Its vapor pressure drops.
B) Its vapor pressure rises.
C) The vapor pressure may rise or drop depending on the liquid.
D) Its vapor pressure is independent of temperature.
E) Its vapor pressure first rises then falls.
18) Which is false? No good answer dropped
A) For a gas sample at constant pressure, temperature and volume are directly proportional.
B) volume α temperature
C) V/T = a constant
V
V
D) 1 = 2
T1
T2
19) All of the following statements describing solutions are false except
A) making a solution involves a chemical change.
B) solutions are heterogeneous.
C) the particles in a solution are atomic or molecular in size.
D) solutions are colorless.
20) In a mixture of 5 mL water, 10 mL alcohol, and 50 mL acetone the solvent(s) is(are)
________.
A) acetone B) alcohol C) water D) acetone and alcohol
21) Which statement best explains the meaning of the phrase "like dissolves like"?
A) A solvent will easily dissolve a solute of similar mass.
B) A solvent and solute with similar intermolecular forces will readily form a solution.
C) The only true solutions are formed when water dissolves a non-polar solute.
D) The only true solutions are formed when water dissolves a polar solute.
22) When a solid dissolves, each molecule is removed from the crystal by interaction with the
solvent. This process of surrounding each ion with solvent molecules is called
A) dilution. B) solvation. C) electrolysis. D) hemolysis.
23) Water can be used to dissolve which type of compounds
A) nonpolar compounds B) polar compounds C) ionic compounds D) both B and C
24) The term miscible is used to describe which type of solution
A) liquid/liquid B) liquid/solid C) gas/liquid D) gas/gas
25) Which of the following should be immiscible with carbon tetrachloride, CCl4?
A) C6H12 B) CH3CH2OH C) Br2 D) C3H8
26) In general, the solubility of ________ in water decreases as temperature increases.
A) gases B) solids C) liquids D) none of these
27) How many grams of NaOH are needed to make 750 mL of a 2.5% (w/v) solution?
A) 3.9 g B) 7.5 g C) 19 g D) 20 g
28) What is the % (w/v) concentration of a solution containing 25.0 g of solute in 400. mL of
solution?
A) 2.50% B) 5.00% C) 6.25% D) 12.5%
29yjughj) What is the % (w/v) concentration of a solution containing 12 grams of solute in 400
mL of solution?
A) 1.2% B) 3.0% C) 4.0% D) 6.0%
30) What is the % (w/v) concentration of a solution containing 25.0 g of solute in 400. mL of
solution?
A) 2.50% B) 5.00% C) 6.25% D) 12.5%
31) Which solution is the most concentrated? Each choice refers to the same solute and solvent.
A) 2.4 g solute in 2 mL solution B) 2.4 g solute in 5 mL solution
C) 20 g solute in 50 mL solution D) 30 g solute in 150 mL solution
32) What is the molarity of a solution prepared by dissolving 0.750 mol CaCl2 in enough water
to make 0.500 L of solution?
A) 0.375 M B) 0.667 M C) 1.50 M D) 83.2 M
33) What is the molarity of a solution prepared by dissolving 10.0 g of acetone, C3H6O, in
enough water to make 125 mL of solution?
A) 4.65 M B) 1.38 M C) 0.0465 M D) 0.0214 M
34) How many mL of 0.105 M AgNO3 are needed for an experiment that requires 0.00510 mol
of AgNO3?
A) 0.536 mL B) 17.8 mL C) 18.70 mL D) 48.6 mL
35) How many mL of a 0.200 M KOH solution contains 10.0 g of KOH?
A) 11.2 mL B) 50.0 mL C) 178 mL D) 891 mL
36) What is the final concentration of a solution prepared by using 75.0 mL of 18.0 M H2SO4 to
prepare 500. mL of solution?
A) 8.33 × 10-3 M B) 1.20 C) 2.70 M D) 2.35 M
37) The passage of a solvent across a semipermeable membrane because of concentration
differences is called
A) dialysis. B) hemolysis. C) hydration. D) osmosis.
38) Which has the highest boiling point?
A) 0.1 M Na2SO4 B) 0.1 M glucose, C6H12O6 C) 0.1 M MgCl2 D) 0.1 M Al(NO3)3
39) If "A" contains 2% NaCl and is separated by a semipermeable membrane from "B" which
contains 10% NaCl, which event will occur?
A) NaCl will flow from "A" to "B". B) NaCl will flow from "B" to "A".
C) Water will flow from "A" to "B". D) Water will flow from "B" to "A".
40) Which solution will have the highest boiling point?
A) 0.050 M KNO3 B) 0.075 M CaCl2 C) 0.025 M NH4NO3 D) 0.020 M Na3PO4