gas aunty pdf

• What is a characteristic of gases that distinguishes them from liquids and solids?

  Gases have compressibility.
• Why are gases easily compressed?

  Because of the large spaces between their molecules.
• What happens to the volume of a gas when pressure is applied?

  The volume decreases as the molecules move closer together.
• What is the expansibility characteristic of gases?

  Gases expand to fill their containers.
• How does the density of gases compare to that of liquids and solids?

  Gases have a low density compared to liquids and solids.
• What is the diffusibility characteristic of gases?

  Gases diffuse easily.
• Do gases have a definite shape or volume?


  No, gases do not have a definite shape or volume.
• How do the molecules of an ideal gas behave?

  They behave like hard, spherical objects in constant random motion.
• In what directions do gases apply pressure?

  Gases apply pressure in all directions.
• What creates pressure in a gas?

  Pressure is created by gas molecules striking the walls of their container.
• What is atmospheric pressure?

  It is the force exerted on a surface by the weight of the air above it.
• How does atmospheric pressure change with altitude?

  Atmospheric pressure decreases as altitude increases.
• What instrument is used to measure atmospheric pressure?

  A barometer is used to measure atmospheric pressure.
• What does the Torricelli Barometer measure?

  It measures atmospheric pressure as the height of a column of mercury.
• What are the units for measuring atmospheric pressure?

  Units are mm Hg or torr.
• How is 1 atm defined in terms of mm Hg?

  1 atm is defined as 760 mm Hg.
• What is the standard pressure in psi?

  1 atm = 14.7 lb/in² (psi).
• What is the SI unit for pressure?

  1 atm = 101,325 Pa.
• What is the relationship between atm and kPa?

  1 atm = 101.325 kPa.
• What is the purpose of a manometer?

  A manometer measures the difference in pressure between atmospheric pressure and that of a gas in a vessel.
• If the height of mercury in the open-end arm of a manometer is 136.4 mm and in the arm in contact with the gas is 103.8 mm, how do you find the pressure of the gas?


  Subtract the height in the gas arm from the height in the open-end arm.
• If atmospheric pressure is 760 mmHg and the mercury column is 60 mm Hg higher on the atmospheric side, what is the pressure on the manometer?

  The pressure on the manometer is 820 mmHg.
• If atmospheric pressure is 760 mmHg and the mercury column is 50 mm Hg lower on the atmospheric side, what is the pressure on the manometer?

  The pressure on the manometer is 710 mmHg.
• What does the Kinetic-Molecular Theory state about gas molecules?

  Gases consist of large numbers of molecules in continuous, random motion.
• What is said about the volume of gas molecules compared to the total volume of the gas?

  The combined volume of all the molecules is negligible relative to the total volume.
• What can be said about attractive and repulsive forces between gas molecules?

  Attractive and repulsive forces between gas molecules are negligible.
• How does energy transfer occur among gas molecules during collisions?

  Energy can be transferred during collisions, but the average kinetic energy remains constant if temperature is constant.
• What is the relationship between average kinetic energy and absolute temperature?

  The average kinetic energy of the molecules is proportional to the absolute temperature.
• What are the main gas laws related to the behavior of gases?

  • Ideal Gas Law
  • Boyle’s Law
  • Charles’s Law
  • Gay-Lussac's Law
  • Combined Gas Law
  • Avogadro’s Law
• What is the Ideal Gas Law equation?

  The Ideal Gas Law is expressed as $PV =$$nRT$.
• What conditions allow real gases to behave like ideal gases?

  Real gases behave like ideal gases at low pressure and high temperature.
• What is the significance of the Ideal Gas Law?

  It describes the behavior of gases and combines Boyle’s, Charles’s, and Avogadro’s laws.
• What must be the temperature unit when using the Ideal Gas Law?

  Temperature must be in Kelvin scale.
• How do you convert Celsius to Kelvin?

  Temperature in Kelvin = Celsius + 273.15.
• In what units should volume be expressed when using the Ideal Gas Law?

  Volume should be expressed in liters.
• What units must pressure be in when using the Ideal Gas Law?

  Pressure units must be in atm.
• How is the amount of gas expressed in the Ideal Gas Law?

  The amount of gas is expressed in moles (n).
• How do you calculate the volume of a gas using the Ideal Gas Law?

  Use the formula $V =$$\frac{nRT}{P}$.
• How do you find the number of moles from a mass of gas?

  Convert grams to moles using the molar mass.
• What is the volume of a 12.0 g sample of Xenon gas at 24.0℃ and 544 mmHg?

  The volume is 3.11 L.