DESCRIBING GASES

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Created by
Zhaine Kryshia

Cards (35)

  • • There are three states of matter, namely solids, liquids, and gases.
  • • All states of matter differ in their properties based on the arrangement of their particles.
  • Solid
    -rigid
    -fixed shape
    -fixed volume
    -cannot be squashed
  • Liquid
    -not rigid
    -no fixed shape
    -fixed volume
    -cannot be squashed
  • Gas
    -not rigid
    -no fixed shape
    -no fixed volume
    -can be squashed
  • PROPERTIES OF GASES
    -Gas is the state of matter that has particles that are freely moving and are far from each other which makes them, "highly compressible"
  • Gases have important fundamental properties that are measurable:
    -Volume
    -Pressure
    -Temperature
    -Amount of the gas or the number of moles.
  • Volume
    -It is the amount of space occupied by a gas sample.
    Its Sl unit is in liters (L)
    milliliters (mL)
    cubic centimeter (cm3)
    cubic meter (m3)
    cubic decimeter (dm3)
  • Pressure
    -Pressure of the gas is the force exerted by the gas per unit area.
    -The SI unit used for pressure is pascal (Pa), named after Blaise Pascal.
  • Other units of pressure are:
    -atmosphere (atm)
    -millimeter of mercury (mmHg)
    -Torr
    -kilopascal (kPa)
    -pounds per square inch (psi)
  • Temperature
    -The temperature of a gas depends. on its kinetic energy.
    -Gases expand when the temperature is increased.
  • The temperature of gas is expressed in:
    -Fahrenheit (°F)
    -Centigrade or Celsius (°C) and
    -Kelvin (K)
  • Though we often use the Celsius degree when dealing with temperature involving involving gases, we always express it in Kelvin temperature.
  • The unit Kelvin was named after Lord Kelvin, a Scottish physicist who has identified the lowest attainable temperature known as absolute zero with a value of -273°C.
  • To convert Celsius to Kelvin, we use the equation K = °C + 273.15
  • Amount of Number of Moles
    -The mass of the gas is related to its number of moles and is generally expressed in kilogram (kg) or gram (g).
  • Equation: Number of moles = mass of the gas/molar mass of the gas
    In symbols, n = m/M
  • KINETIC MOLECULAR THEORY OF GAS
    -The properties of gases can explained in terms of their molecular motion.
    -The ideas about molecular motion were developed into the kinetic molecular theory by Rudolf Clausius, James Maxwell, and Ludwig Boltzman.
  • KINETIC MOLECULAR THEORY OF GAS Their postulates on the behavior of gases are:
    1. A gas consists of very small particles. The particles are in constant, random, and straight- line motion.
    2. The particles of a separated by distances much larger than their size.
    3. The gas particles collide with each other and with the walls of the container in a perfectly elastic manner.
    4. The average kinetic energy of the gas particles is proportional to the absolute (Kelvin) temperature. As the temperature increases, the gas particles move faster.
  • BOYLE'S LAW
    -at constant temperature, the volume of the gas increases as the pressure decreases. The volume of the gas decreases and the pressure increases.
  • Formula for Boyle's Law
    P1V1 = P2V2
  • CHARLES' LAW
    -French Chemist Jacques Charles discovered that the volume of a gas at constant pressure changes with temperature.
  • CHARLES' LAW
    -From his experiment on balloons, Charles observed that, at constant pressure, the volume of gas increases with every increase in temperature. Also, volume decreases as temperature decreases.
  • Charles' Law states that the volume of a gas is directly proportional to the absolute temperature provided the pressure remains constant.
  • CHARLES' LAW
    • If the temperature of a gas increases, the volume increases. If the temperature decreases, the volume of a gas decreases.
  • Mathematical equation of a Charles' Law:
    V1/T1=V2/T2
    V1 = Initial Volume
    V2= Final Volume
    T1 = Initial Temperature
    T2= Final Temperature
  • CHARLES' LAW
    The temperature must be the Absolute temperature expressed in a "Kelvin (K)" scale. °C+ 273.15
  • JOSEPH LOUIS GAY-LUSSAC
    -The person who who is credited with the determination of the temperature-pressure relationship in gases at constant volume.
  • JOSEPH LOUIS GAY-LUSSAC
    -He deduced that the pressure of the gas is directly proportional to its temperature.
  • GAY-LUSSAC'S LAW
    When the temperature of gases increases, its pressure also increases or vice versa.
  • GAY-LUSSAC'S LAW
    -At constant volume, the pressure of a fixed mass of gas is directly proportional to the absolute temperature.
  • GAY-LUSSAC'S LAW EQUATION
    P1/T1 = P2/T2
    P1=Initial Pressure
    P2=Final Pressure
    T1=Initial Temperature
    T2=Final Temperature
  • COMBINED GAS LAW
    -Boyle's Law and Charles' Law can be combined and treated as a single law, called the combined gas law, which describes the pressure-volume- temperature relationship of α constant amount of gas.
  • COMBINED GAS LAW
    -The pressure and volume of a gas are inversely proportional to each other, but are both directly proportional to the temperature of that gas.
  • COMBINED GAS LAW EQUATION
    P1V1/T1 = P2V2/T2
    P1=Initial Pressure
    P2=Final Pressure
    T1=Initial Temperature
    T2=Final Temperature
    V1=Initial Volume
    V2=Final Volume