CHAPTER TEST: STUDY OF GAS LAWS

Class: 9

Full Marks: 20

Time: 30 mins.

• Ques. 1 Choose the correct option: [5]

  • Which of the following statements best describes Boyle's Law?

    • A: The volume of a gas is directly proportional to its temperature at constant pressure.

    • B: The volume of a gas is inversely proportional to its temperature at constant pressure.

    • C: The volume of a gas is directly proportional to its pressure at constant temperature.

    • D: The volume of a gas is inversely proportional to its pressure at constant temperature.

  • Which of the following is true for absolute zero?

    • A: Molecules are at random motion at this temperature.

    • B: Volume of gases are maximum at this temperature.

    • C: Molecular motion of gas ceases at this temperature.

    • D: All three states of matter can exist at this temperature.

  • The boiling point of water is:

    • A: 100K

    • B: 200K

    • C: 273K

    • D: 373K

  • Which of the following statement is correct?

    P: At constant pressure, the volume of the fixed mass of dry gas is directly proportional to temperature.

    Q: At constant pressure, the volume of the fixed mass of dry gas is directly proportional to absolute temperature.

    • A: Only P

    • B: Only Q

    • C: Both P & Q

    • D: Neither P nor Q

  • Assertion (A): When stating the volume of a gas, the pressure and temperature should also be given.

    Reason (R): Volume of a gas depends on the temperature & pressure of the gas.

    • A: Both A & R are true and R is the correct explanation of A.

    • B: Both A & R are true and R is the correct explanation of A.

    • C: A is true but R is false.

    • D: A is false but R is true.

• Ques.2. Fill in the blanks with the words/ phrases given in the bracket: [5]

  • The volume of the gas is ____________, when the Kelvin temperature is doubled at constant pressure. (doubled/ halved)

  • The graph of PV vs P for a gas is _____________. (a straight line parallel to X- axis/ a straight line passing through the origin)

  • Volume-temperature relationship of gases is given by ____________. (Boyle’s law/ Charles ‘law)

  • The standard temperature is ___________ . (0C/ 0K)

  • At constant temperature, the volume of the gas ____________ with increase of pressure. (increases/ decreases)

• Ques. 3. State if the following statements are true or false. Justify your answer. [5]

  • Negative temperatures are not possible on the Kelvin scale.

  • Inflating a balloon violates Boyle’s law.

  • It is not possible to keep the volume of a fixed mass of dry gas same by changing the temperature & pressure.

  • When the temperature of a gas is increased, the pressure of the gas also increases if the volume remains the same.

  • No gas can exist at absolute temperature.

• Ques 4.

  • 270 L of a gas at 27C is cooled to standard temperature at constant pressure. What will be the new volume of the gas? [2]

  • A gas is enclosed in a cylinder at STP. Keeping the pressure constant, if the volume is doubled what will be the new temperature? [1]

  • 2 L of a gas is enclosed in a vessel at a pressure of 760 mm Hg. If temperature remains constant, calculate pressure when volume changes to 4 L [2]

Name : _______________________________

Date : _______________________________