Deck 10: Gases

Question 1

Which of the following organic compounds would you expect to be a gas at room temperature?

A) Carbon tetrachloride
B) Butanol
C) Acetylene
D) Methanol
E) Benzaldehyde

Answer 1

Acetylene

Question 2

The amount of force (F) exerted on a given area (A) of surface is given by the formula _____.

Answer 2

P = F/A

Question 3

In a barometer the area above the column of mercury is a(n) _____.

Answer 3

vacuum

Question 4

Hydrogen bromide is a gas at 25°C and 1.0 atm.

Question 5

What is the pressure in SI units exerted by a cup with a diameter of 7.00 cm and a weight of 400.0 gm?

A) 19.6 kPa
B) 3.92 kPa
C) 1.02 kPa
D) 23.0 kPa
E) 35.3 kPa

Question 6

_____ and mercury are the only liquid elements at room temperature.

Question 7

What is a manometer? Describe the construction and working of a closed-end manometer.

Question 8

Which of the following gases exists naturally as a triatomic molecule?

A) Ozone
B) Argon
C) Krypton
D) Neon
E) Hydrogen

Question 9

Both allotropes of oxygen are gasses at 25°C and 1.0 atm.

Question 10

The elements that occur naturally as gases are on the _____ side of the periodic table.

Question 11

Based on their position in the periodic table, which of the following would be a gas?

A) Potassium
B) Ruthenium
C) Vanadium
D) Hydrogen
E) Calcium

Question 12

What are the different types of gaseous compounds?

Question 13

At constant temperature, the volume of a fixed amount of a gas is directly proportional to its pressure.

Question 14

The force exerted by an object does not depend on its orientation.

Question 15

Ionic compounds exist as gases at room temperature and pressure.

Question 16

Every point on Earth's surface experiences a net pressure called _____.

Question 17

Which of the following elements exists naturally as a monatomic gas?

A) Nitrogen
B) Hydrogen
C) Chlorine
D) Argon
E) Oxygen

Question 18

Which of the following is not a gas at room temperature?

A) Hydrogen
B) Fluorine
C) Bromine
D) Iodine
E) Mercury

Question 19

A man weighing 750 kg stands on a stool. If the stool has four legs and each leg equals a surface area of 25 cm², what is the pressure exerted by the man on the floor?

A) 75.0 kPa
B) 735 kPa
C) 105 kpa
D) 1880 Pa
E) 147 kPa

Question 20

Among the three common phases of matter, gases have the lowest density.

Question 21

At constant temperature and volume, the pressure exerted by a gas depends on only the total number of moles of gas present.

Question 22

The value of the universal gas constant in terms of J/K.mol is 0.082057.

Question 23

Which equation is an accurate representation of Boyle's law?

A) P = V
B) P ? V
C) PV = 0
D) V = $\frac { \text { constant } } { P }$
E) P = $\frac { V } { \text { constant } }$

Question 24

The _____ of a gas is 22.41 L at STP.

Question 25

Explain Robert Boyle's J-shaped tube experiments that determined the quantitative relationship between the pressure and the volume of a gas.

Question 26

Two moles of argon (monatomic), under the same conditions will exert the same pressure as one mole of hydrogen (monatomic).

Question 27

The volume of an ideal gas at 0 K and 1 atm will be _____.

Question 28

_____ liters of sulfur dioxide will contain the same number of particles as 3 liters of oxygen at the same temperature and pressure.

Question 29

An oxygen cylinder with an empty volume of 31.4 L contains oxygen stored at 3.000 * 10³ psi at 25.0˚C. How many moles of oxygen are contained within the cylinder?

A) 204 mol
B) 4.19 mol
C) 835 mol
D) 8.35 mol
E) 419 mol

Question 30

At constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute_____.

Question 31

_____ law states that at constant temperature and pressure, the volume of a sample of gas is directly proportional to the number of moles of gas in the sample.

Question 32

Equal volumes of methane, ammonia, chlorine, and hydrogen are kept at the same temperature and pressure. Which of the following is true of the gases?

A) All the gases will have the same mass.
B) Hydrogen having the lowest molecular weight will be present in greater quantity.
C) The amount of methane and ammonia will be double that of hydrogen and nitrogen since they have twice the number of atoms.
D) Since equal volumes of the gases are present at the same conditions the number of moles of the gases will be the same.
E) Chlorine and hydrogen being non-polar will have least intermolecular attraction, hence fewer number of moles of these gases will be present.

Question 33

In the perfect gas equation, R is the gas constant. What is the value of R in (L·atm)/(K·mol)?

A) 0.082057
B) 8.314
C) 6.022 *10²³
D) 1.9872
E) 273

Question 34

A ball of clay with air inside it is sealed at 25.0°C and 1.00 atm. The ball is heated steadily until it explodes at 60.0°C. What is the pressure inside the ball of clay before it explodes?

A) 1.12 atm
B) 4.60 atm
C) 3.80 atm
D) 19.3 atm
E) 22.1 atm

Question 35

PV = nRT is known as the ideal gas law.

Question 36

How many moles of an ideal gas are present in 22.4 L of a gas at 0.00˚C and 1.00 atm?

A) 22.4
B) 6.02
C) 3.00
D) 1.00
E) 11.2

Question 37

At what temperature will the volume of a gas be equal to zero?

A) 0˚C
B) -273.15 K
C) 273.15 K
D) 0 K
E) 273.15˚C

Question 38

All gasses will have zero volume at a temperature of -273.15˚C.

Question 39

What is an ideal gas? Why is the concept of an ideal gas important?

Question 40

One mole of a gas at 25˚C at a pressure of 2 atms has a volume of 17.8 L. What will the volume of the gas be at a temperature of 35˚C?

A) 16.4 L
B) 12.7 L
C) 17.8 L
D) 18.4 L
E) 22.4 L

Question 41

Explain the water displacement method used for collecting and measuring the volume of a gas.

Question 42

The partial pressures of oxygen in atmospheric air and in air exhaled by a human are in the ratio of 4:3. If the mole fraction of oxygen in atmospheric air is 0.210 what is mole fraction of oxygen in exhaled air?

A) 0.213
B) 1.02
C) 0.750
D) 0.158
E) 0.237

Question 43

Ammonia cannot be collected via the water displacement technique because it dissolves in water.

Question 44

Methane burns according to the formula: CH₄ + 2O₂ $\rightarrow$ CO₂ + 2H₂O
What volume of carbon dioxide in liters will be released at STP when 12.0 g of CH₄ is burnt?

A) 44.4 L
B) 1220 L
C) 16.8 L
D) 841 L
E) 1710 L

Question 45

A 30.0 L liquefied petroleum gas cylinder consists of 55% propane by mass and 45% of butane. If the total mass of the liquefied gases is 23.0 kg, then what is the partial pressure exerted by propane in the cylinder at 25.0˚C? Molar mass of propane is 44.096 g/mol.

A) 24.1 atm
B) 17.2 atm
C) 29.6 atm
D) 14.01 atm
E) 34.79 atm

Question 46

A 30.0 L liquefied petroleum gas cylinder consists of 55.0% propane by mass and 45.0% of butane. If the total volume of the liquefied gases is 23.0 kg, then what is the total pressure exerted of the gaseous mixture in the cylinder at 25.0˚C? Given: Molar mass of propane is 44.096 g/mol

A) 82.5 atm
B) 0.825 atm
C) 11.5 atm
D) 0.425 atm
E) 42.5 atm

Question 47

Potassium superoxide absorbs carbon dioxide and releases oxygen according to the formula: 4KO₂ + 2CO₂ $\rightarrow$ 2K₂CO₃ + 3O₂
How much potassium superoxide would be required to absorb 12 liters of CO₂ at 30˚C and 1140 mmHg?

A) 454 g
B) 71.0 g
C) 103 g
D) 1.44 g
E) 0.719 g

Question 48

The vapor pressure of water at 0˚C is zero.

Question 49

Write a note on mole fractions of gas mixtures.

Question 50

The total pressure exerted by a mixture of gases is the _____ of the partial pressures of the components

Question 51

The partial pressures of oxygen in atmospheric air and in air exhaled by a human are in the ratio of 4:3. If the mole fraction of oxygen in atmospheric air is 0.21, how much oxygen is utilized per liter of air breathed?

A) 5.2 mL
B) 11 mL
C) 158 mL
D) 14 mL
E) 21 mL

Question 52

If P_A is the pressure of a gas A, P_t is the pressure of the total gas mixture, X_A is the mole fraction of the gas A, P_A = X_AP_t.

Question 53

Gases like fluorine and HF cannot be collected by the water displacement method because they _____ with water.

Question 54

The partial pressure of a gas is independent of the pressure exerted by all other gases present.

Question 55

The pressure exerted by each gas in a gas mixture is called the gas's_____.

Question 56

An oxygen cylinder used by scuba divers contains 21% of oxygen (mimicking air). Pure oxygen at a pressure above 1 atmosphere is toxic. If the undersea pressure increases by one atmosphere every 33 feet, how deep can a diver using the oxygen cylinder dive before the oxygen gets toxic?

A) 99 ft.
B) 112 ft
C) 174.67 ft
D) 157ft
E) 225 ft

Question 57

Potassium superoxide absorbs carbon dioxide and releases oxygen according to the formula: 4KO₂ + 2CO₂ $\rightarrow$ 2K₂CO₃ + 3O₂
How much potassium superoxide would be required to produce 80.0 liters of oxygen at 30.0˚C and 1140 mmHg?

A) 458 g
B) 6.40 g
C) 74.8 g
D) 107 g
E) 4.00 g

Question 58

The _____ of any component of a mixture is the ratio of the number of moles of that substance to the total number of moles of all substances present.

Question 59

Water undergoes hydrolysis according to the following formula: 2H₂O + $\rightarrow$ O₂ + 2H₂
If the hydrogen produced is captured in a glass tube, and the hydrogen captured measures 5.00 mL then how many molecules of water would have undergone electrolysis, when the pressure inside the tube is 1 atm at a temperature of 22.0˚C? The vapor pressure of water at 22.0˚C is 19.84 mmHg.

A) 0.000210 mol
B) 123 mol
C) 0.748 mol
D) 0.0600 mol
E) 0.120 mol

Question 60

Mole fraction of A = $\frac { \text { total moles } } { \text { moles } A }$ , where moles A $\rightarrow$ 0.

Question 61

In a gas, attractive intermolecular forces produce a pressure that is more than that expected based on the ideal gas law.

Question 62

A 25.0 L cylinder contains 2.50 *10² g of CH₄. What is the pressure in the cylinder at 27.0°C calculated using van der Waals equation?

A) 2850 kPa
B) 1510 kPa
C) 3870 kPa
D) 4870 kPa
E) 5870 kPa

Question 63

What is the mean free path of a gas molecule? Explain with examples.

Question 64

The speed of 8 particles were found to be 2, 2, 4, 5, 5, 7, 6, and 6 m/s, the root mean squared speed of the particles are _____ m/s.

A) 5.000
B) 4.937
C) 24.37
D) 37.00
E) 1.348

Question 65

Hydrogen consists of two isotopes ¹H and ²H with atomic masses 1.007 and 2.014 respectively. If gaseous ¹H₂ is to be separated from gaseous ²H₂ by gaseous diffusion what is the ratio of effusion rates of the gaseous forms of the isotopes?

A) 2.22
B) 1.41
C) 1.00
D) 3.86
E) 1.61

Question 66

Hydrogen consists of two isotopes ¹H and ²H with atomic masses 1.007 and 2.014 respectively. If gaseous ¹H₂ is to be separated from gaseous ²H₂ by gaseous diffusion how many steps are necessary to yield 99% pure ²H₂? The natural abundance of ²H₂ is 0.0150%.

A) 8.345
B) 11.89
C) 25.60
D) 18.56
E) 6.789

Question 67

Effusion is the escape of gaseous molecules through a small hole into an evacuated space.

Question 68

The root mean squared speed of a gas particle increases as the temperature of the gas _____.

Question 69

The volume of a container containing a gas is increased by 50%. Which of the following quantities decreases?

A) Average velocity of the gas particles
B) Root mean squared speed of the gas particles
C) Average speed of the gas particles
D) Force exerted by the gas per unit area of the container
E) The number of gas particle within the container

Question 70

In van der Waals equation, the correction for volume is negative and the correction for pressure is positive.

Question 71

Particles of different gases at the same temperature have the same average speed.

Question 72

A 10.0 L cylinder contains 370.0 g of N₂. Its pressure to three significant figures at 27.0 °C calculated using van der Waals equation is _____.

A) 31.9 atm
B) 9.50 atm
C) 325 atm
D) 2.36 atm
E) 456 atm

Question 73

What is the root mean squared speed of a sample of neon at 50˚C?

A) 6.31 × 10² m/s²
B) 11.4 × 10² m/s²
C) 20.5 × 10² m/s²
D) 18.5 × 10² m/s²
E) 6.77 × 10² m/s²

Question 74

The vapor pressure of water _____ with increasing temperature.

Question 75

As the density of a gas decreases, the mean free path becomes _____.

Question 76

_____ is the gradual mixing of gases due to the motion of their component particles even in the absence of mechanical agitation such as stirring.

Question 77

The average kinetic energy of the molecules of any gas is dependant on the size of the particles of the gas.

Question 78

How does the kinetic molecular theory of gases explains the relationship between pressure and volume?

Question 79

At the boiling point of water the vapor pressure of water is _____ atm.

Question 80

A 10.0 L cylinder contains 370 g of N₂. What is the difference in the pressure at 27°C calculated using van der Waals equation, and the pressure calculated using the ideal gas equation?

A) 0 atm
B) 0.620 atm
C) 1.35 atm
D) 2.35 atm
E) 1.35 atm.