The Gas Laws and the Ideal Gas Equation · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

One equation for every gas

Science · Matter & Materials · ages 15-17
Name ______________________   Date ____________

  1. Gas at 100 kPa fills 2.0 L. It expands slowly to 4.0 L at constant temperature. What is the new pressure in kPa?

    Answer: ______________

  2. A fixed mass of gas in a sealed can is heated from 300 K to 600 K. What happens to its pressure?

    • Doubles
    • Halves
    • Stays the same
    • Quadruples

  3. A sealed can of gas is heated from 300 K to 600 K. What happens to its pressure?

    • Doubles
    • Halves
    • Stays the same

  4. Plugging 200 C straight into p V = n R T gives the right answer.

    Circle one:   True   False

  5. Gas is squeezed at constant temperature. What shape is its p against V graph?

    • A falling curve
    • A straight line through the origin
    • A flat horizontal line
    • A rising curve

  6. A sealed gas cools from 300 K to 250 K. What happens to its pressure?

    • It rises above the start
    • It stays exactly the same
    • It falls to five sixths

  7. 2.0 mol of gas sits in 3.0 m3 at 300 K. Use R = 8.31 and p V = n R T. What is the pressure in pascals?

    Answer: ______________

  8. 2.0 mol of gas sits in 3.0 m3 at 300 K. Use R = 8.31 and p V = n R T. What is the pressure in pascals?

    Answer: ______________

  9. A syringe of gas is warmed and its plunger moves freely. Which relation lets pressure stay set?

    • V over T stays constant at fixed pressure
    • p times T stays constant at fixed volume
    • n times R stays constant at fixed moles

  10. Two gas samples share T and p. Sample B holds twice the moles of A. How do volumes compare?

    • B is half the volume of A
    • Both volumes match exactly
    • B is twice the volume of A
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Answer key

For grown-ups. Fold this page away before handing over the rest.

One equation for every gas W1-mt_G7DOTVl4KM-s1

  1. 50 · At fixed T, p times V is constant: 100 x 2 / 4 = 50 kPa.
  2. Doubles · With V fixed, p over T is constant, so doubling T doubles p.
  3. Doubles · With volume fixed, p over T is constant, so doubling T doubles p.
  4. False · The equation needs absolute temperature, so convert to kelvin first.
  5. A falling curve · At fixed T, pressure is proportional to 1 over V, which draws a hyperbola.
  6. It falls to five sixths · p follows T in kelvin, so 250 over 300 leaves five sixths of the pressure.
  7. 1662 · p = n R T / V = 2 x 8.31 x 300 / 3 = 1662 Pa.
  8. 1662 · p = n R T / V = 2 x 8.31 x 300 / 3 = 1662 Pa.
  9. V over T stays constant at fixed pressure · Free plunger means pressure fixed, so volume grows in step with kelvin temperature.
  10. B is twice the volume of A · In p V = n R T with T and p fixed, volume scales directly with moles.
Worksheet · LightMySky