AP Chem Ch. 5 Review

All of the following are postulates of kinetic-molecular theory of gases except: a) At a constant temp, each molecule has the same kinetic energy b) The gas molecules are in rapid motion c) The collisions between molecules are elastic d) The gas molecules are in constant motion e) The volumes of the molecules are negligible compared with the volume of the container

a) At a constant temp, each molecule has the same kinetic energy

A gas sample is held at constant pressure. The gas occupies 3.62 L of volume when the temp is 21.6 degrees C. Determine the temp at which the volume of the gas is 3.42 L a) 295 K b) 312 K c) 278 K d) 552 K e) 20.4 K

c) 278 K

Order the following in increasing rate of effusion: F2, Cl2, NO, NO2, CH4

c) Cl2 < NO2 < F2 < NO < CH4

Four identical 1.0 flasks contain the gases He, Cl2, CH4, NH3, each at 0 degrees C and 1 atm pressure For which gas do the moleucles have the highest average velocity? a) CH4 b) Cl2 c) He d) NH3 e) all gases have the same

c) He

When 0.72 g of a liquid is vaporized at 110°C and 0.967 atm, the gas occupies a volume of 0.559 L. The empirical formula of the gas is CH2. What is the molecular formula of the gas? a) C2H4 b) C4H8 c) C3H6 d) CH2 e) none of these

c) C3H6

Which of the following would have a higher rate of effusion that C2H2 a) Cl2 b) O2 c) CH4 d) N2 e) CO2

c) CH4

What would happen to the average kinetic energy of the molecules of a gas sample if the temp of the sample increased from 20 degrees C to 40 degrees C? a) It would double b) It would decrease c) It would increase d) It would become half its value e) Two of these

c) It would increase

Graham's law states that: a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure b) Equal amounts of gases occupy the same volume at constant temp and pressure c) The rates of effusion of gases are inversely proportional to the square roots of their molar masses d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

c) The rates of effusion of gases are inversely proportional to the square roots of the molar masses

You have a certain mass of helium gas (He) in a rigid steel container. You add the same mass of neon gas (Ne) to this container. Which of the following best describes what happens? Assume the temp is constant a) The pressure in the container doubles b) The pressure in the container more than doubles c) The volume of the container doubles d) The volume of the container more than doubles e) The pressure in the container increases, but does not double

e) The pressure in the container increases, but does not double

Dalton's law of partial pressures states that: a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure b) Equal amounts of gases occupy the same volume at constant temp and pressure c) The rates of effusion of gases are inversely proportional to the square roots of their molar masses d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

Four identical 1.0 flasks contain the gases He, Cl2, CH4, NH3, each at 0 degrees C and 1 atm pressure For which gas are the molecules diatomic? a) CH4 b) Cl2 c) He d) NH3 e) all gases have the same

b) Cl2

Calculate the root mean square velocity for the O2 molecules in a sample of O2 gas at 11.8 degrees C (R=8.3145 J/K mol) a) 471.2 m/s b) 272.0 m/s c) 8.973 x 10^26 m/s d) 14.90 m/s e) 95.91 m/s

a) 471.2 m/s

Charles's law states that: a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure b) Equal amounts of gases occupy the same volume at constant temp and pressure c) The rates of effusion of gases are inversely proportional to the square roots of their molar masses d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure

Gases generally have a) low density b) no increase in volume when temp is increased c) high density d) no decrease in volume when pressure is increased e) closely packed particles

a) low density

The standard temp for gases is a) 100 degrees C b) 0 degrees C c) 32 degrees C d) 212 degrees F e) 0 degrees F

b) 0 degrees C

The partial pressure of CH4, N2, and O2 in a sample of gas were found to be 135 mmHg, 508 mmHg, and 571 mmHg, respectively. Calculate the mole faction of nitrogen a) 0.470 b) 0.418 c) 0.751 d) 20.4 e) 0.359

b) 0.418

Standard pressure for gases is a) 100 atm b) 1 atm c) dependent upon the temp d) 0 atm e) none of these

b) 1 atm

A gas sample is heated from -20.0 degrees C to 57.0 degrees C and the volume is increased from 2.00 L to 4.50 L. If the initial pressure is 0.140 atm, what is the final pressure? a) -0.177 atm b) 0.242 atm c) 0.0811 atm d) 0.0477 atm e) 0.411 atm

c) 0.0811 atm

Calculate the ratio of effusion rates of N2 and N2O a) 1.61 b) 0.637 c) 1.57 d) 0.798 e) 1.25

e) 1.25

The mass of 1.12 L of gas Y at STP is found to be 6.23g. The molar mass of gas Y is a) 140. g/mol b) 89.0 g/mol c) 56.0 g/mol d) 157 g/mol e) 125 g/mol

e) 125 g/mol

An excess of sodium hydroxide is treated with 26.5 L of dry hydrogen chloride gas measure at STP. What is the mass of sodium chloride formed? a) 0.138 kg b) 1.55 kg c) 69.1 g d) 1.69 g e) 13.3 g

e) 13.3 g

Consider a sample of gas in a container on a comfortable spring day. The C temp suddenly doubles, and you transfer the gas to a container with twice the volume of the first container. If the original pressure was 12 atm, what is a good estimate for the new pressure? a) 5.5 atm b) 15 atm c) 12 atm d) 3 atm e) 6.4 atm

e) 6.4 atm

Four identical 1.0 flasks contain the gases He, Cl2, CH4, NH3, each at 0 degrees C and 1 atm pressure Which gas sample has the greatest number of molecules? a) CH4 b) Cl2 c) He d) NH3 e) all gases have the same

e) all gases the same

What volume does 40.5g of N2 occupy at STP? a) 50.7 L b) 64.8 L c) 32.4 L d) 1.81 L e) none of these

c) 32.4 L

Avogadro's law states that: a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure b) Equal amounts of gases occupy the same volume at constant temp and pressure c) The rates of effusion of gases are inversely proportional to the square roots of their molar masses d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

b) Equal amounts of gases occupy the same volume at constant temp and pressure

Which of the following is not a postulate of kinetic molecular theory? a) The forces of attraction and repulsion between the particles are insignificant b) Gas particles have most of their mass concentrated in the nucleus of the atom c) The moving particles undergo perfectly elastic collisions with the walls of the container d) The average kinetic energy of the particles is directly proportional to the absolute temp e) All of the above are postulate of the kinetic molecular energy

b) Gas particles have most of their mass concentrated int eh nucleus of the atom

Use the kinetic molecular theory of gases to predict what would happen to a closed sample of a gas whose temp increased while its volume decreased a) Its pressure would hold constant b) Its pressure would increase c) Its pressure would decrease d) The number of moles of the gas would decrease e) The average kinetic energy of the molecules of the gas would decrease

b) Its pressure would increase

A glass column is filled with mercury and inverted in a pool of mercury. The mercury column stabilizes at a height of 729 mm above the pool of mercury. What is the pressure of the atm? a) 0.729 atm b) 1.04 atm c) 0.959 atm d) 0.639atm e) 456 atm

c) 0.959 atm

For a gas, which two variables are directly proportional to each other (if all other conditions remain constant)? 1. T and n 2. V and n 3. V and T a) 2 only b) 1 only c) 2 and 3 only d) 3 only e) 1 and 2 only

c) 2 and 3 only

A sample of 35.1 g of methane gas has a volume of 3.11 L at a pressure of 2.70 atm. Calculate the temp a) 35.0 K b) 32.4 K c) 320 K d) 46.8 K e) 2.92 K

d) 46.8 K

Which of the following is true about eh kinetic molecular theory? a) The volume of a gas particle is considered to be small - about 0.10 mL b) Gas particles repel each other, but do not attract one another c) Adding is an ideal gas to a closed container will cause an increase in temp d) Pressure is due to the collisions of the gas particles with the walls of the container e) At lease two of teh above statements are correct

d) Pressure is due to the collisions of the gas particles with the walls of the container

Boyle's Law states that: a) The volume of a fixed amount of gas is directly proportional to its temp in Kelvin at constant pressure b) Equal amounts of gases occupy the same volume at constant temp and pressure c) The rates of effusion of gases are inversely proportional to the square roots of their molar masses d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp e) The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds

d) The volume of a fixed amount of gas is inversely proportional to its pressure at constant temp