A LevelChemistryCambridge (CIE)Exam Questions4. States of MatterThe Gaseous State: Ideal & Real Gases & pV = nRT

The Gaseous State: Ideal & Real Gases & pV = nRT (Cambridge (CIE) A Level Chemistry): Exam Questions

Exam code: 9701

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The Gaseous State: Ideal & Real Gases & pV = nRT

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1
1 mark

For an ideal gas at constant pressure and temperature, which diagram shows the graph of pV against n?

  • Graph of pV against n showing a straight line that does not pass through the origin
  • Graph of pV against n showing a curved line
  • Graph of pV against n showing a horizontal straight line, indicating pV is constant as n increases
  • Graph of pV against n showing a straight line through the origin

Choose your answer

2
1 mark

The Mr value of a gas can be calculated from the general gas equation. 

Which expression will give the value of Mr for a sample of a gas of mass m grams?

  • Mr= fraction numerator m R T over denominator p V end fraction

  • Mr = fraction numerator p V R T over denominator m end fraction

  • Mr = begin mathsize 16px style fraction numerator m p V over denominator R T end fraction end style

  • Mr = fraction numerator p V over denominator m R T end fraction

Choose your answer

3
1 mark

Which gas least resembles an ideal gas at room temperature?

  • Ammonia

  • Carbon dioxide

  • Helium

  • Hydrogen

Choose your answer

4
1 mark

The ideal gas equation below summarises the gas laws. 

pV = nRT

Which statement below is correct?

  • Intermolecular forces of attraction exist between gas molecules.

  • Ideal gas molecules collide inelastically upon impact with each other.

  • One mole of an ideal gas occupies the same volume under the same conditions of temperature and pressure.

  • The volume of a given mass of an ideal gas is doubled if its temperature is raised from 25℃ to 50 ℃.

Choose your answer

1
1 mark

Under which conditions of pressure and temperature is the calculated value of Mr most accurate when using the ideal gas equation?

Pressure

Temperature

A

Low

High

B

Low

Low

C

High

High

D

High

Low

    Choose your answer

    2
    1 mark

    0.96 g of hydrogen gas is contained in a sealed vessel of volume of 7.0 × 10−3 m3 at a temperature of 303 K. 

    Assume the gas behaves as an ideal gas. 

    What is the pressure of the vessel?

    • 172.7 Pa

    • 173 kPa

    • 345 kPa

    • 691.1 kPa

    Choose your answer

    3
    1 mark

    A 5370 cm3 sample of oxygen is measured at a temperature of 60 °C. The pressure measured was 103 kPa.

    Assume the gas behaves as an ideal gas.

    What is the mass of the sample of oxygen?

    • 1.8 g

    • 3.2 g

    • 3.6 g

    • 6.4 g

    Choose your answer

    4
    1 mark

    A sample of chlorine gas with a mass of 5.35 g has a volume of 1.247 × 10−3 m3 at a pressure of 1.00 × 105 Pa.

    Assuming the gas acts as an ideal gas, what is the temperature of the gas?

    • 100 K

    • 200 K

    • 250 K

    • 300 K

    Choose your answer

    5
    1 mark

    A bubble rose from the sea bed to the surface. The bubble had a volume of 200 cm3 at a pressure of 101 kPa just below the surface. The temperature at the sea bed and the surface are the same.

    The pressure at the sea bed is 2020 kPa. Assume the gas behaves as an ideal gas.

    What is the volume of the bubble at the sea bed?

    • 10 cm3

    • 200 cm3

    • 100 cm3

    • 4000 cm3

    Choose your answer

    6
    1 mark

    Sodium reacts with water in the equation below.

    2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)

    Which mass of sodium reacts with water to produce 960 cm3 of hydrogen gas at r.t.p.?

    • 0.46 g

    • 0.91 g

    • 1.81 g

    • 3.68 g

    Choose your answer

    7
    1 mark

    At 298 K and 101 kPa, which is the only compound that exists as a gas?

    • 1-aminopropane

    • Chloroethane

    • Ethane-1,2-diol

    • Propan-1-ol

    Choose your answer

    8
    1 mark

    When a sample of a gas is compressed at room temperature from 101 kPa to 300 kPa, its volume changes from 50.0 cm3 to 17.5 cm3.

    Which statement best explains this observation?

    • Gas is adsorbed on to the vessel walls.

    • The gas behaves ideally.

    • The gas behaves non-ideally.

    • The gas partially liquefies.

    Choose your answer

    9
    1 mark

    1 mol of a gas occupies 24 dm3 at r.t.p.

    Which gas sample occupies a volume of 3 dm3 at r.t.p.?

    • 2.0 g of CH4

    • 4.0 g of He

    • 4.4 g of CO2

    • 7.0 g of N2

    Choose your answer

    10
    1 mark

    Plots of pV against p for three real gases W, X, Y and an ideal gas are shown below.

    Graph of pV against p for an ideal gas and three real gases labelled W, X and Y. The ideal gas is shown as a horizontal line. Gas X stays closest to the ideal gas line, gas W shows moderate positive deviation at high pressure, and gas Y shows the greatest deviation, dipping below the ideal gas line at intermediate pressures.

    Which row gives the identities of gases W, X and Y?

    W

    X

    Y

    A

    H2

    N2

    NH3

    B

    H2

    NH3

    N2

    C

    N2

    H2

    NH3

    D

    N2

    NH3

    H2

      Choose your answer

      11
      1 mark

      Which expression gives the pressure exerted by 1.5 × 10−2 mol of carbon dioxide in a container of volume 2 dm3 at 275 °C? Assume the gas behaves as an ideal gas.

      • fraction numerator open parentheses 1.5 space cross times space 10 to the power of negative 2 space end exponent close parentheses space cross times space 8.31 space cross times space 275 over denominator 2 space cross times space 10 to the power of negative 6 end exponent end fraction

      • fraction numerator stretchy left parenthesis 1.5 space cross times space 10 to the power of negative 2 space end exponent stretchy right parenthesis space cross times space 8.31 space cross times space stretchy left parenthesis 275 space plus space 273 stretchy right parenthesis over denominator 2 space cross times space 10 to the power of negative 6 end exponent end fraction

      • fraction numerator stretchy left parenthesis 1.5 space cross times space 10 to the power of negative 2 space end exponent stretchy right parenthesis space cross times space 8.31 space cross times space stretchy left parenthesis 275 space plus space 273 stretchy right parenthesis over denominator 2 space cross times space 10 to the power of negative 3 end exponent end fraction

      • fraction numerator stretchy left parenthesis 1.5 space cross times space 10 to the power of negative 2 space end exponent stretchy right parenthesis space cross times space 8.31 space cross times space 275 over denominator 2 space cross times space 10 to the power of negative 3 end exponent end fraction

      Choose your answer

      1
      1 mark

      A tube of volume 0.3 dm3 is filled with a gas at 27 °C and 101 kPa. The mass of the tube increases by 1.02 × 10−3 kg. Assume the gas behaves ideally.

      What is the identity of the gas?

      • Helium

      • Krypton

      • Neon

      • Oxygen

      Choose your answer

      2
      1 mark

      A sample of methane has a volume of 5.25 dm3 at 50 °C and 102 kPa. Assuming the gas behaves ideally, what is the mass of the sample to two significant figures?

      • 0.0018 g

      • 0.0032 g

      • 0.18 g

      • 3.2 g

      Choose your answer

      3
      1 mark

      2.0 g of a metallic element reacts with 599 cm3 of oxygen at r.t.p., forming an oxide that contains O2– ions.

      What is the identity of the metal?

      • Calcium

      • Magnesium

      • Potassium

      • Sodium

      Choose your answer

      4
      1 mark

      The volume of a sample of ammonia was measured at a temperature of 60 °C and a pressure of 75 kPa. The volume measured was 5.27 × 10–5 m3. Assume the gas behaves as an ideal gas.

      What is the mass of the sample of ammonia?

      • 2.4 × 10–5 g

      • 2.5 × 10–4 g

      • 2.4 × 10–2 g

      • 2.5 × 10–1 g

      Choose your answer

      5
      1 mark

      When an evacuated tube of volume 560 cm3 is filled with gas at 340 K and 101 kPa, the mass of the tube increases by 0.8 g. Assume the gas behaves as an ideal gas.

      Which noble gas has been added to the tube?

      • Argon

      • Helium

      • Krypton

      • Neon

      Choose your answer

      6
      1 mark

      The glass containers X and Y are connected by a closed valve.

      Diagram showing two glass containers labelled X and Y connected by a closed valve. Container Y has a volume three times that of container X.

      X contains pure CO2 gas at 25 °C and a pressure of 1 × 105 Pa. Container Y has been evacuated prior to the experiment and has a volume three times the volume of container X.

      During the experiment, the valve is opened and the temperature of the whole apparatus is raised to 160 °C. Assume the gas behaves ideally.

      What is the final pressure in the system?

      • 2.13 × 105 Pa

      • 3.60 × 105 Pa

      • 4.24 × 104 Pa

      • 3.63 × 104 Pa

      Choose your answer

      7
      1 mark

      0.84 g of a metallic element reacts completely with 5000 cm3 of oxygen at 441 K and 22 kPa. Assume the gas behaves ideally. The oxide formed contains O2– ions.

      What is the identity of the metal?

      • Aluminium

      • Lithium

      • Magnesium

      • Sodium

      Choose your answer

      8
      1 mark

      Flask Q contains 4 dm3 of neon at 10 kPa pressure, and flask R contains 10 dm3 of helium at 5 kPa pressure. Assume the gases behave ideally.

      The flasks are connected at constant temperature. What is the final pressure in the system?

      • 6.4 kPa

      • 7.5 kPa

      • 9.0 kPa

      • 15 kPa

      Choose your answer

      9
      1 mark

      The atmospheric composition of four different planets is given in the table below.

      Under the same conditions of temperature and pressure, which atmosphere is the most dense?

      Planet

      Major gases / % by number of molecules

      A

      Jupiter

      H2 89.6, He 10.4

      B

      Neptune

      H2 81.0, He 18.0, CH4 1.0

      C

      Saturn

      H2 96.2, He 3.5, CH4 0.25

      D

      Uranus

      H2 81.5, He 16.2, CH4 2.3

        Choose your answer

        10
        1 mark

        The product of pressure and volume (pV) is plotted on the y-axis against temperature (T) in kelvin on the x-axis for one mole of an ideal gas.

        What is the gradient of the resulting straight-line graph?

        • 1/R

        • p

        • R

        • V

        Choose your answer