Practice Quiz 20

Choose the best answer

  1. Which of the following is a correct statement.
    1. Boyle's law states that if the temperature of a
      gas is kept constant, then the volume and
      the pressure of the gas are inversely proportional.
    2. Charles' law states that if pressure is kept
      constant, then the volume and the
      temperature of the gas are inversely proportional
    3. Boyle's law states that if the temperature of a
      gas is kept constant, then the volume and
      the pressure of the gas are directly proportional.
    4. Charles' law states that if the temperature of a
      gas is kept constant, then the volume and
      the pressure of the gas are inversely proportional.
    5. The combined gas law states that the volume of a
      gas is directly proportional to its pressure and
      inversely proportional to its temperature.
    Answer: A

  2. Which of the following is not a correct
    statement?
    1. One mole of any ideal gas has a volume of 22.4
      liters at STP.
    2. One mole of any substance contains avogadro
      number of molecules.
    3. one mole of a substance and one gram molecular
      weight of a substance have the same mass.
    4. gram molecular weight of a compound is equal to
      the molecular mass of the compond expressed
      in grams.
    5. Atomic mass of an element is the mass of one
      atom of the element expressed in grams.
    Answer: E

  3. A gas has a volume of 60 L at a pressure of 30 kPa and a
    temperature of 30 �C. Calculate its volume at a pressure of
    35 kPa and a temperature of 15 �C.
    1. 78.169 L
    2. 17.707 L
    3. 65.425 L
    4. 57.655 L
    5. 48.883 L
    Answer: E

  4. A gas in a balloon has a volume of 70 L at a pressure
    of 40 kPa. Calculate its pressure when its volume
    is changed to 95 L at constant temperature.
    1. 36.577 kPa
    2. 29.474 kPa
    3. 46.178 kPa
    4. 49.193 kPa
    5. 17.796 kPa
    Answer: B

  5. How many moles are there in a gas that occupies
    a volume of 18 L at a pressure of 120 kPa and a
    temperature of 60 �C.
    1. 0.517
    2. 1.424
    3. 1.147
    4. 0.633
    5. 0.782
    Answer: E

  6. Calculate the temperature of 20 g of di-atomic chlorine ( Cl2 )
    gas that occupies a volume 900 L at a pressure of 50 kPa.
    (atomic mass of chlorine is 35 u ).
    1. 28021.521 �C
    2. 18702.904 �C
    3. 23208.062 �C
    4. 5945.081 �C
    5. 8825.449 �C
    Answer: B

  7. How many molecules are there in a sample of gas
    that occupies a volume 5 L at STP.
    1. 0.429e23
    2. 1.93e23
    3. 0.216e23
    4. 2.343e23
    5. 1.344e23
    Answer: E

  8. A 20 g sample of di-atomic hydrogen ( H2 ) gas is at a
    temperature of 90 �C. Calculate the average energy
    (translational kinetic energy) of one hydrogen
    molecule of the sample.
    1. 5.622e-21 J
    2. 12.164e-21 J
    3. 8.29e-21 J
    4. 7.514e-21 J
    5. 0.944e-21 J
    Answer: D

  9. A 40 g sample of di-atomic oxygen ( O2 ) gas is at a
    temperature of 20 �C. Calculate the total energy
    (translational kinetic energy) of the sample. (atomic mass
    of oxygen is 16 u. )
    1. 7573.419 J
    2. 8436.765 J
    3. 4559.813 J
    4. 5948.824 J
    5. 576.491 J
    Answer: C

  10. A 80 g sample of di-atomic Chlorine ( Cl2 ) gas is at a
    temperature of 60 �C. Calculate the RMS (root
    mean square) speed of the molecules of the sample.
    (atomic mass of Chlorine i is 35 u. )
    1. 642.293 m ⁄ s
    2. 188.81 m ⁄ s
    3. 151.331 m ⁄ s
    4. 344.17 m ⁄ s
    5. 259.056 m ⁄ s
    Answer: D