A LevelChemistryCIEExam Questions4. States of Matter4.1 The Gaseous State: Ideal & Real Gases & pV = nRT

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

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

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

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11 mark

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

  • 1-4-e-2a

  • 1-4-e-2b

  • 1-4-e-2c

  • 1-4-e-2d

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21 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

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31 mark

Which of the following least resembles an ideal gas at room temperature?

  • Helium

  • Ammonia

  • Carbon dioxide

  • Hydrogen

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41 mark

The ideal gas equation below summarises the gas laws. 

                              pV = nRT

Which statement below is correct?

  • There exist intermolecular forces of attraction between gas molecules.

  • Ideal gas molecules will 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 ℃.

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11 mark

An experiment is conducted to calculate the Mr of an unknown gas of known mass. 

Measurements of pressure, volume and temperature are taken during the experiment.

Which conditions of temperature and pressure would give the most accurate value of Mr?

 

Pressure

Temperature

A

Low

High

B

Low

Low

C

High

High

D

High

Low

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    21 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

    • 172.7 kPa

    • 345.5 Pa

    • 691.1 kPa

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    31 mark

    A 5370 cm3 sample of oxygen is measured at a temperature of 60°C. The pressure measured was 103000 Pa. 

    Assume the gas behaves as an ideal gas.

    What is the mass of the sample of oxygen?

    • 3.2 g

    • 6.4 g

    • 1.8 g

    • 3.6 g

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    41 mark

    A sample of chlorine gas with a of mass 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?

    • 300 K

    • 250 K

    • 100 K

    • 200 K

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    51 mark

    A bubble travelled up from the sea bed to the surface. Just below the surface of the sea the bubble had a volume of 200 cm3 at a pressure of 101 kPa, the temperature at the surface is the same as the sea bed.

    The pressure at the sea bed is 2020 kPa.

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

    • 10 cm3

    • 200 cm3

    • 100 cm3

    • 1000 cm3

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    61 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 under standard pressure and room temperature?

    • 3.68 g

    • 1.81 g

    • 0.91 g

    • 0.46 g

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    71 mark

    At 298 K and 101 kPa which compound is the only gas?

    • Chloroethane

    • 1-aminopropane

    • Propan-1-ol

    • Ethane-1, 2-diol

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    81 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 describes why this happens?

    • The gas behaves ideally.

    • The gas behaves non-ideally.

    • Gas is absorbed on to the vessel walls.

    • The gas partially liquifies.

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    91 mark

    What mass of a gas would occupy a volume of 3 dm3 at 25 ℃ and 1 atmosphere pressure? 

    1 mol of a gas occupies 24 dm3 at 25 ℃ and 1 atmosphere pressure.

    • 7.0 g of N2

    • 4.4 g of CO2

    • 4.0 g of He

    • 2.0 g of CH4

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    101 mark

    Real gases deviate from ideal behaviour. The extent to which they deviate depends on the identity of the gas.  

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

    1-4-diagram-q11m

    What are the identities of gases W, X, Y? 

     

    W

    X

    Y

    A

    N2

    NH3

    H2

    B

    N2

    H2

    NH3

    C

    H2

    N2

    NH3

    D

    H2

    NH3

    N2

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      111 mark

      Which expression gives the pressure exerted by 1.5 × 10-2 mol of carbon dioxide in a container of volume 2 dm-3 at 275 ℃?

      • 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

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      11 mark

      A tube of volume 0.3 dm3 is filled with a gas at 27 ℃ and 101 kPa, the mass of the tube increases by 1.02 cross times10-3 kg. 

      Assume the gas is obeying the ideal gas laws. 

      What is the identity of the gas?

      • Neon

      • Helium

      • Oxygen

      • Krypton

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      21 mark

      The volume of a sample of methane is measured at a temperature of 50 ℃ and a pressure of 102 kPa, The volume measured was 5.25 dm3. [R = 8. 314 J mol-1 K-1] 

      What is the mass of the sample of methane, given to two significant figures?

      • 0.0018 g

      • 3.20 g

      • 0.0032 g

      • 0.18 g

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      31 mark

      2.0 g of a metallic element reacts with 599 cm3 of oxygen at 298 K and 1 atm pressure, to form an oxide which contains O2– ions.

      What could be the identity of the metal?

      • Magnesium

      • Calcium

      • Sodium

      • Potassium

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      41 mark

      Use of the periodic table is relevant to this question.

      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.

      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

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      51 mark

      The gas laws can be summarised in the ideal gas equation below.

      pV = nRT

      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?

      • Helium

      • Neon

      • Argon

      • Krypton

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      61 mark

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

      1-4-h-6

      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 bigger than container X. 

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

      What is the final pressure in the system?

      • 2.13 × 105 Pa

      • 3.60 × 105 Pa

      • 4.24 × 104 Pa

      • 3.6 × 104 Pa

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      71 mark

      0.84 g of a metallic element reacts completely with 5000 cm3 of oxygen at 441 K and 22 kPa pressure to form an oxide which contains O2– ions.

      What could be the identity of the metal?

      • Lithium

      • Magnesium

      • Aluminium

      • Sodium

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      81 mark

      Flask Q contains 4 dm3 of neon at 10 kPa pressure, and flask R contains 10 dm3 of helium at 5 kPa pressure.

      If the flasks are connected at a constant temperature, what is the closest final pressure?

      • 6 kPa

      • 8 kPa

      • 9 kPa

      • 10 kPa

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      91 mark

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

      The density of a gas can be defined as the mass of 1 dm3 of the gas measured at standard conditions. 

      Which atmosphere is the most dense?

       

      Planet

      Major gases / % by number of molecules

      A

      Jupiter

      H2 89.6, He 10.4

      B

      Saturn

      H2 96.2,  He 3.5,  CH4 0.25

      C

      Uranus

      H2 81.5,  He 16.2,  CH4 2.3

      D

      Neptune

      H2 81.0,  He 18.0,  CH4 1.0

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