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