Ideal Gases (Edexcel IGCSE Physics)

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  • True or False?

    The particles in a gas are in constant random motion at high speeds.

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Cards in this collection (35)

  • True or False?

    The particles in a gas are in constant random motion at high speeds.

    True.

    The particles in a gas are in constant random motion at high speeds.

  • True or False?

    Gases moving in random motion collide with the surfaces of the container and with other gas particles.

    True.

    Gases moving in random thermal motion collide with the surfaces of the container and with other gas particles.

  • What causes the pressure in a gas when it is contained?

    Pressure in a gas is caused by collisions of the gas particles with the walls of the container.

  • State the equation for pressure.

    The equation for pressure due to contact between two surfaces is P space equals fraction numerator space F over denominator A end fraction

    Where:

    • P = pressure, measured in pascals (Pa)

    • F = force, measured in newtons (N)

    • A = area, measured in metres squared (m2)

  • Define pressure.

    Pressure is force per unit area.

  • Define Brownian motion.

    The random motion of tiny particles in a fluid is known as Brownian motion.

  • True or False?

    It is possible to have negative values of temperature in degrees kelvin.

    False.

    It is not possible to have negative values of temperature in degrees kelvin. 0 K is absolute zero, the lowest possible temperature.

  • True or False?

    10 °C = 283 K

    True.

    0 °C = 273 K, and an increase of 1 °C is equal to an increase in 1 K. Therefore, 10 °C = 283 K

  • Describe the motion of particles at absolute zero.

    At absolute zero, particles are stationary.

  • True or False?

    Ice melts at 0 K.

    False.

    Ice melts at 0 °C and 0 °C = 273 K. 0 K is equal to –273 °C.

  • A gas experiences a temperature change of 26.4 °C. What is the change in its temperature in kelvin?

    The gas experiences a temperature change of 26.4 K, as an increase of 1 K is the same size as an increase of 1 °C.

  • True or False?

    Absolute temperature is inversely proportional to kinetic energy of gas particles.

    False.

    Temperature is directly proportional to kinetic energy of gas particles.

  • Define temperature.

    Temperature is a measure of the average speed of particles in a substance.

  • True or False?

    If the average kinetic energy of particles in a gas doubles, the temperature in kelvin doubles.

    True.

    Temperature in kelvin is directly proportional to the kinetic energy of gas particles.

  • What happens to the average speed of particles when a gas cools down?

    When a gas cools down, the average speed of particles decreases.

  • True or False?

    The frequency of collisions between particles in a container with a fixed volume increases because of a decrease in temperature.

    False.

    The frequency of collisions between particles in a container with a fixed volume decreases because of a decrease in temperature.

  • What are the two relationships linking pressure, temperature and volume described by the gas laws?

    The two relationships described by the gas laws are:

    • Pressure and temperature

    • Pressure and volume

  • When a gas is compressed, how does its volume change?

    When a gas is compressed, its volume decreases.

  • When a gas expands, how does its volume change?

    When a gas expands, its volume increases.

  • True or False?

    When the volume of a gas increases at constant temperature, its pressure increases too.

    False.

    When the volume of a gas increases, the pressure of the gas decreases.

  • True or False?

    When the temperature of a gas increases at constant volume, its pressure increases too.

    True.

    When the temperature of a gas increases, its pressure also increases.

  • True or False?

    When the volume of a gas is decreased at a constant temperature, the frequency of the collisions between particles and container walls remains constant.

    False.

    When the volume of a gas is decreased, the frequency of collisions between particles and container walls increases.

  • True or False?

    Increasing the temperature of a gas at fixed volume increases the average speed of particles. This reduces the frequency of collisions with the container walls so pressure increases.

    False.

    Increasing the temperature of a gas at a fixed volume increases the frequency of collisions with the container walls because speed increases.

  • True or False?

    For a given temperature and volume, a higher pressure gas has particles with more average kinetic energy.

    False.

    Temperature is a measure of particle speed, so if the temperature is the same, so is the average kinetic energy of particles.

  • Air is contained in the chamber sealed by the piston. What change in gas pressure causes the piston to move in the direction shown? Assume temperature remains constant.

    Diagram showing air in a cylinder pushing a piston to the right. Parts labelled: "Air" inside the cylinder, "Cylinder," and "Piston" at the cylinder's end. Arrow indicates direction to the right.

    A pressure increase causes the piston to move right, because the volume of the gas increases.

  • True or False?

    The pressure law states that pressure is inversely proportional to volume.

    False.

    The pressure law states that pressure is proportional to temperature.

  • True or False?

    When pressure doubles at constant volume, the temperature increases from 100 °C to 200 °C.

    False.

    It is the temperature in kelvin that will double, not temperature in degrees Celsius, as pressure is proportional to absolute temperature.

  • What is the equation linking initial temperature and pressure (T1 and p1) and final temperature and pressure (T2 and p2) for a gas heated at fixed volume?

    The equation linking the initial and final temperatures and pressures is p subscript 1 over T subscript 1 space equals space p subscript 2 over T subscript 2

  • What is the pressure law equation when rearranged to make initial pressure p subscript 1 the subject?

    The pressure law with initial pressure as the subject is p subscript 1 space equals space p subscript 2 over T subscript 2 space cross times space T subscript 2

  • On a graph of pressure against temperature in degrees Celsius for a gas with fixed volume, what is the value of temperature when pressure is 0 Pa?

    When pressure is 0 Pa this occurs at –273 °C.

    Graph showing the direct relationship between pressure and temperature with the x-axis labelled 'Temperature (°C)' and the y-axis labelled 'Pressure.' The line crosses the x axis at a temperature of minus 273 degrees Celsius.
  • Define Boyle's law.

    Boyle's law states that the pressure of a gas at a constant temperature is inversely proportional to its volume.

  • State the equation for Boyle's law.

    The equation for Boyle's law is p subscript 1 V subscript 1 space equals space p subscript 2 V subscript 2

    Where:

    • p subscript 1 = initial pressure, measured in pascals (Pa)

    • p subscript 2 = final pressure, measured in pascals (Pa)

    • V subscript 1 = initial volume, measured in metres cubed (m3)

    • V subscript 2 = final volume, measured in metres cubed (m3)

  • What is the equation for Boyle's law with the final volume V subscript 2 as the subject?

    The equation for Boyle's law in terms of final volume is V subscript 2 space equals fraction numerator space p subscript 1 V subscript 1 over denominator p subscript 2 end fraction

    Where:

    • V subscript 2 = final volume, measured in metres cubed (m3)

    • p subscript 1 = initial pressure, measured in pascals (Pa)

    • p subscript 2 = final pressure, measured in pascals (Pa)

    • V subscript 1 = initial volume, measured in metres cubed (m3)

  • True or False?

    On a graph of pressure against volume at a fixed temperature, the line is curved and does not cross the x axis.

    True.

    The pressure vs volume graph shows an inversely proportional relationship. This is a curve which does not touch either axis.

  • True or False?

    This graph shows the pressure law.

    Graph showing an inversely proportional relationship between pressure and volume; as pressure increases, volume decreases. Axes are labelled "Volume" (vertical) and "Pressure" (horizontal).

    False.

    The graph shows Boyle's law.