Syllabus Edition

First teaching 2014

Last exams 2024

|

Modelling a Gas (DP IB Physics: SL)

Exam Questions

3 hours42 questions
1
Sme Calculator
1 mark

What force does a particle of an ideal gas experience with a pressure of 166 kPa on an area of 2.0 m2?

  • 83 000 N

  • 332 000 N

  • 0.083 N

  • 0.332 N

Did this page help you?

2
Sme Calculator
1 mark

A fixed mass of an ideal gas is trapped in a cylinder of constant volume and its temperature is varied. Which graph shows the variation of the pressure of the gas with temperature in kelvin?

3-2-q2-sl-easy-mcq-phy

    Did this page help you?

    3
    Sme Calculator
    1 mark

    Which row gives the correct definitions for nN and NA?

      n N NA
    A.  number of molecules  Avogadro's constant  Avogadro's constant
    B. Avogadro's constant Avogadro's constant  number of molecules
    C. Avogadro's constant number of moles number of molecules
    D. number of moles  number of molecules Avogadro's constant

      Did this page help you?

      4
      Sme Calculator
      1 mark

      A sealed container contains a mixture of helium and neon gas. 

      The ratio of fraction numerator mass space of space straight a space neon space molecule over denominator mass space of space straight a space helium space molecule end fraction is 5. 

      What is the correct ratio for fraction numerator average space kinetic space energy space of space neon space molecules over denominator average space kinetic space energy space of space helium space molecules end fraction?

      • 1 fifth

      • 1

      • 5

      • Dependent on the concentration of each gas

      Did this page help you?

      5
      Sme Calculator
      1 mark

      Which statement describes a correct assumption for the kinetic model of an ideal gas?

      • The kinetic energy of a given molecule of the gas is constant.

      • The forces between each gas molecule varies.

      • The intermolecular potential energy of the molecules of the gas varies.

      •  The momentum of a given molecule of the gas varies upon a collision with the container.

      Did this page help you?

      6
      Sme Calculator
      1 mark

      The volume of an ideal gas in a container is decreased at constant temperature.

      Which of the following statements are correct about the molecules of the gas?

      I.   Their average kinetic energy increases.

      II.  The frequency of the collisions per unit area of the container wall increases.

      III. The pressure of the gas increases.

      • I only

      • I and III only

      • II and III only 

      • I and II only

      Did this page help you?

      7
      Sme Calculator
      1 mark

      Which of the following is not an assumption of the kinetic model of ideal gases?

      • All particles in the gas have different speeds.

      • The duration of collisions between particles is long in comparison to the time between the collisions.

      • There are no intermolecular forces between the particles in the gas.

      • Collisions with the walls of the container are elastic.

      Did this page help you?

      8
      Sme Calculator
      1 mark

      Which graph shows the correct relationship between the volume, V ,and pressure, p, of a gas kept at a constant temperature?

      question-1-1

        Did this page help you?

        9
        Sme Calculator
        1 mark

        Which condition allows the behaviour of a monatomic gas, such as argon, to approximate to that of an ideal gas? 

        • Low pressure.

        • High temperature.

        • High density.

        • Very low temperature.

        Did this page help you?

        10
        Sme Calculator
        1 mark

        Which of the following is not an equation used for an ideal gas?

        • pVnRT

        • P over V= constant

        • V over T= constant

        • fraction numerator p V over denominator T end fraction= constant

        Did this page help you?

        1
        Sme Calculator
        1 mark

        A fixed mass of an ideal gas is at temperature T K. The pressure is quadrupled, and the volume is halved. What is the temperature after these changes?

        • T over 2

        • 2 T

        • T over 4

        • T

        Did this page help you?

        2
        Sme Calculator
        1 mark

        A fixed mass of an ideal gas undergoes an isovolumetric change. This leads to a decrease in the pressure of the gas.

        Which row describes the change in internal energy of the gas and the direction of transfer of thermal energy?

         

        Internal Energy

        Direction of thermal energy transfer

        A.

        greater

        to the gas

        B.

        greater

        from the gas

        C.

        less

        to the gas

        D.

        less

        from the gas

          Did this page help you?

          3
          Sme Calculator
          1 mark

          A fixed mass of an ideal gas is initially at an absolute temperature, T and occupies a volume, V

          The gas is adjusted so that the final pressure of the gas is twice the magnitude of the initial pressure.

          Which row of the table below, A to D, gives the correct expressions for the final volume and temperature of the gas?

           

          Final volume of the gas

          Final temperature of the gas

          A.

          4 V 2 T

          B.

          2 V T over 4

          C.

          V over 2 4 T

          D.

          V over 4 T over 2

            Did this page help you?

            4
            Sme Calculator
            1 mark

            The graphs, A to D, show the variation of pV with θ for one mole of two different gases, nitrogen and chlorine, where p is the pressure of the gas, V is the volume of the gas and θ is the temperature in °C.

            Which graph shows the correct variation of pV with θ for 1 mole of each gas?

            question-8

              Did this page help you?

              5
              Sme Calculator
              1 mark

              X and Y are two flasks containing an ideal gas that are connected by a tube that has negligible volume compared with the volume of each flask. The volume of X is twice the volume of Y.

              The temperature of the gas in X is kept at 200 K and the temperature of the gas in Y is kept at 400 K.

              If the mass of the gas in X is MX and the mass of the gas in Y is MY, what is the ratio size 16px M subscript size 16px X over size 16px M subscript size 16px Y?

              • 1 over 8

              • 1 fourth

              • 4

              • 8

              Did this page help you?

              6
              Sme Calculator
              1 mark

              An ideal gas of fixed mass has a pressure, p, and volume, V. The graph shows the variation of 1 over p with V at a constant temperature.

              question-17-1

              Which line represents the same gas if the thermodynamic temperature and the amount of gas are doubled?

              3.2-Modelling-a-Gas-MCQs-question-17-2-

                Did this page help you?

                7
                Sme Calculator
                1 mark

                Given the following data:

                • Mass of oxygen = 16 g
                • Temperature = 27 °C
                • Length of side of cubic container = 10 cm
                • Mass of one mole of oxygen = 32 g

                What is the pressure of oxygen in a cubic container?

                • 1 kPa

                • 12 kPa

                • 110 kPa

                • 1200 kPa

                Did this page help you?

                8
                Sme Calculator
                1 mark

                A sealed cylinder of radius r and length L contains an ideal gas. The gas is at pressure p and temperature T. The radius of the cylinder is halved, and the temperature is altered to maintain the same pressure.

                Which of these is an expression for the new temperature of the gas?

                • T over 4

                • T over 2

                • 2 T

                • 4 T

                Did this page help you?

                9
                Sme Calculator
                1 mark

                An ideal gas of N molecules is maintained at constant volume, V. The graph shows how temperature T varies with pressure p.

                q20_modelling-a-gas_ib-sl-physics-mcq

                What is the gradient of the graph?

                • fraction numerator size 16px V size 16px N subscript size 16px A over denominator size 16px N size 16px R end fraction

                • fraction numerator size 16px V size 16px N over denominator size 16px N subscript size 16px A size 16px R end fraction

                • fraction numerator size 16px N size 16px R over denominator size 16px V size 16px N subscript size 16px A end fraction

                • n R V

                Did this page help you?

                1
                Sme Calculator
                1 mark

                A fish swimming in a lake expels an air bubble at a depth of 30.0 m. At this depth the temperature of the water is −33 °C and the pressure is four times the pressure at the surface. The bubble rises to the surface where the temperature is 27 °C. 

                What is the percentage change of the volume of the air bubble as it rises to the surface from a depth of 30.0 m?

                • 20 %

                • 100 %

                • 400 %

                • 600 %

                Did this page help you?

                2
                Sme Calculator
                1 mark

                The variation of pressure with temperature is shown on the graph for a fixed mass of an ideal gas at constant volume. 

                3-2-sl-mcq-hard-q2-phy

                What is the ratio of pressure and temperature of the ideal gas?

                • 200 Pa K−1

                • 300 Pa K−1

                • 400 Pa K−1

                • 500 Pa K−1

                Did this page help you?

                3
                Sme Calculator
                1 mark

                A mass of 5 × 10−3 kg of Hydrogen is split between two gas bottles Y and Z. Y and Z are connected by a tube that has a negligible volume compared with the volume of each bottle. 

                3-2-sl-mcq-hardh-q4-phy

                Initially the valve X is closed and gas bottle Y has a volume 4V and contains Hydrogen at a pressure p. Gas bottle Z has a volume and contains Hydrogen at a pressure of 3p. Y and Z are initially at the same temperature. 

                X is now opened.

                What is the new gas pressure assuming there is no change in temperature?

                • 3 over 8 p

                • 1 over 6 p

                • 8 over 5 p

                • 7 over 5 p

                Did this page help you?

                4
                Sme Calculator
                1 mark

                A materials scientist carries out an experiment to investigate the relationship between the volume and temperature of an ideal gas. The pressure of the gas is kept constant throughout the experiment. Two of their readings are shown below. 

                Temperature / °C

                Volume of gas / cm3

                0

                55

                100

                76

                What is the value for absolute zero that can be calculated from these results? 

                • −273.15 °C

                • −261.9 °C

                • 0 °C

                • 100 °C

                Did this page help you?

                5
                Sme Calculator
                1 mark

                An ideal gas is initially at a temperature of 127 °C. It is heated and the root mean square velocity of the gas is then tripled. Use 1 × 10−23 as the Boltzmann Constant. 

                 

                Kinetic Energy /J

                Temperature °C

                A.

                6 × 10−21

                3000

                B.

                5.4 × 10−20

                3600

                C.

                6 × 10−21

                3327

                D.

                5.4 × 10−20

                3327

                What are the values for the temperature of the gas and the mean kinetic energy of the molecules after it has been heated?

                  Did this page help you?

                  6
                  Sme Calculator
                  1 mark

                  A single molecule of mass 5 × 10−28 kg moves with a speed of 200 m s−1 in a rigid cubical container with a side length of 0.4 m. 

                  3-2-sl-mcq-hard-q7-phy

                  Assume all collisions between the molecule and the walls of the container are perfectly elastic.

                  What is the average pressure exerted on the wall by the molecule?

                  • 5.0 × 10−23 Pa

                  • 1.25 × 10−22 Pa

                  • 3.125 × 10−22 Pa 

                  • 6.35 × 10−20 Pa

                  Did this page help you?

                  7
                  Sme Calculator
                  1 mark

                  Air consists of 0.9% argon molecules and 0.002% neon molecules. Argon has a relative molecular mass of 40 and neon a relative molecular mass of 20.

                  What is the ratio of the root mean square speed of argon to that of neon molecules in the air?

                  • square root of 1 half end root

                  • square root of 1 fourth end root

                  • square root of 1 over 8 end root

                  • square root of 2 over 9 end root

                  Did this page help you?

                  8
                  Sme Calculator
                  1 mark

                  In a car factory laboratory, the atmospheric pressure is 101 kPa and the temperature is 47 °C. The pressure in the car tyre under investigation is 180 kPa and the temperature 227 °C.

                  Assume no air is lost from the tyre.

                  What is the percentage increase in the root mean square speed of the air molecules due to the experiment?

                  • 10%

                  • 20%

                  • 25%

                  • 30%

                  Did this page help you?

                  9
                  Sme Calculator
                  1 mark

                  An ideal gas is stored in a sealed container of fixed volume and has molecules with a root mean square speed of m s−1. The temperature of the gas changes resulting in a decrease in pressure by one-third of the previous value.

                  What is the new expression for the root mean square speed of the molecules after the temperature has changed?

                  • fraction numerator c squared over denominator square root of 3 end fraction

                  • fraction numerator c over denominator square root of 3 end fraction

                  • c over 3

                  • c square root of 3

                  Did this page help you?