TB_Gases

Question 1

The following are observed characteristics of gases except for
a. gases can be compressed by application of pressure
b. gases diffuse and spontaneously mix with each other
c. pressure exerted by a gas decreases with increase in temperature
d. there is negligible attraction between particles of an ideal gas

Answer 1

c. pressure exerted by a gas decreases with increase in temperature

Question 2

The standard pressure of the atmosphere at sea level is
a. 1 atm
b. 760 mm Hg
c. 760 torr
d. all of the above

Answer 2

d. all of the above

Question 3

. As altitude increases, air becomes less dense and
a. pressure increases
b. pressure decreases
c. pressure remains the same
d. none of the above

Answer 3

b. pressure decreases

Question 4

Raising the temperature of an enclosed gas
a. slows down the kinetic energy of the gas molecules
b. decreases the momentum of the gas molecules
c. forces the gas particles to collide with the walls harder
d. decreases the volume of the gas

Answer 4

c. forces the gas particles to collide with the walls harder

Question 5

At constant temperature and pressure, the rate of diffusion of a gas varies
a. inversely as its density
b. directly as its molecular mass
c. directly as the square root of its density
d. inversely as the square of its molecular mass

Answer 5

d. inversely as the square of its molecular mass

Question 6

What are the standard temperature and pressure (STP) conditions for gas law problems?
a. 760 atm, 00C
b. 1 mm Hg, 2730C
c. 760 mmHg, 273 K
d. 760 atm, 0 K

Answer 6

c. 760 mmHg, 273 K

Question 7

If the temperature of a confined gas is doubled, while the volume is held constant, what will happen to
the pressure?
a. it will be doubled
b. it will be half as large
c. it will be four times as large
d. cannot be determined

Answer 7

a. it will be doubled

Question 8

What happens to the volume of a fully inflated balloon when it is taken outside on a cold day?
a. its volume decreases
b. it remains the same
c. its volume increases
d. its volume becomes equal to zero

Answer 8

a. its volume decreases

Question 9

The process by which a gas under pressure escapes from a compartment of a container to another by
passing through a small opening is called
a. effervescence
b. effusion
c. diffusion
d. sublimation

Answer 9

b. effusion

Question 10

As a bubble of air rises from a diver’s helmet to the surface of the water, it continuously expands.
What law is illustrated?
a. Dalton’s law
b. Avogadro’s law
c. Boyle’s law
d. Charles’ law

Answer 10

c. Boyle’s law

Question 11

A gas is in a steel tank at 100 atm pressure. When the tank is opened to the atmosphere, the gas
suddenly expands, increasing its volume by 10%. This illustrates
a. Dalton’s law
b. Boyle’s law
c. Charles’ law
d. Gay-Lussac’s law

Answer 11

b. Boyle’s law

Question 12

Water boils at a lower temperature such as on top of a mountain than at sea level. This illustrates
a. Boyle’s law
b. Charles’ law
c. Graham’s law
d. Avogadro’s law

Answer 12

b. Charles’ law

Question 13

What volume is occupied by 4.00 g of carbon dioxide, CO2 (44.0) gas at a pressure of
0.976 atm and a temperature of 25.00C?
a. 0.191 L
b. 19.1 L
c. 2.28 L
d. 22.8 L

Answer 13

c. 2.28 L

Question 14

What is the molar mass of an unknown gas if 1.60 grams of that gas occupies a volume of
2.24 L at STP?
a. 16.0 g/mol
b. 35.8 g/mol
c. 81.0 g/mol
d. 160 g/mol

Answer 14

a. 16.0 g/mol

Question 15

he volume of a certain gas sample is 235 ml when collected over water at a temperature of 250C and
a pressure of 698 mm Hg. What will be the volume of this gas when measured dry at standard
conditions? The vapor pressure of water at this temperature is 23.8 mm Hg.
a. 197 ml
b. 191 ml
c. 223 ml
d. 265 ml

Answer 15

b. 191 ml

Question 16

The depletion of ozone, O3, in the stratosphere has been a matter of great concern among scientists in
recent years. It is believed that ozone can react with nitric oxide, NO, that is discharged from
high-altitude jet plane, the SST. The reaction is
O3 + NO → O2 + NO2
If 0.740 g of O3 reacts with 0.670 g of NO, how many grams of NO2 would be produced?
( O, 16.0; N, 14.0)
a. 0.0708 g
b. 0.1026 g
c. 0.708 g
d. 1.026 g

Answer 16

c. 0.708 g

Question 17

What is the limiting reagent in problem #16?
a. O3
b. O2
c. NO
d. NO2

Answer 17

a. O3

Question 18

What is the number of moles of the excess reagent remaining at the end of the reaction in problem #16?
a. 0.0690
b. 0.690
c. 0.00069
d. 0.0069

Answer 18

d. 0.0069

Question 19

Which of the following represents the largest gas pressure?
a. 1.0 atm
b. 1.0 Pa
c. 1.00 mm Hg
d. 1.0 KPa

Answer 19

a. 1.0 atm

Question 20

The total volume of a average adult lungs when expanded is about 6 liters. Calculate the pressure of
oxygen inhaled if 0.05 mole of oxygen is needed to fully fill a pair of average adult lungs at a
normal body temperature of 370C.
a. 0.0253 atm
b. 2.58 atm
c. 0.212 atm
d. 0.308 atm

Answer 20

c. 0.212 atm

Question 21

Molecular oxygen is highly soluble in the blood because
a. the hemoglobin molecule can bind up to four oxygen molecules
b. the solubility of oxygen is increased by the higher temperature of the body
c. pressure is increased inside the body
d. pressure inside the body is different outside of it

Answer 21

a. the hemoglobin molecule can bind up to four oxygen molecules

Question 22

. A fatal condition known as “bends” occurs when a diver ascends too quickly to the surface of the water.
This is due to
a. nitrogen in the blood boiling off rapidly as its partial pressure decreases, forming bubbles
in the blood
b. lack of oxygen in water at depths of more than 15 meters
c. the solubility of oxygen gas is very much decreased at greater depths
d. the solubility of oxygen decreases in the blood as the diver ascends

Answer 22

a. nitrogen in the blood boiling off rapidly as its partial pressure decreases, forming bubbles
in the blood

Question 23

When water is heated in a beaker, bubbles of air form on the side of the glass before the water boils.
This shows that
a. the solubility of gases in water decreases with increasing temperature
b. the solubility of gases in water increases with increasing temperature
c. the solubility of gases in water decreases with decreasing temperature
d. the solubility of gases in water increases with decreasing temperatur

Answer 23

a. the solubility of gases in water decreases with increasing temperature