The Gas Laws

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The Gas Laws

• And what they can do for me!
• D

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Put Simply.

• The gas laws are a series of rules and equations
  used to determine how a gas will react to various
  changes in its established situation.

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Put simply-er

• These are the rules used to tell what will happen
  to a gas when stuff happens.

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Here is what will be covered

• Boyles law for pressure.
• Charles law for temperature.
• Gay Lussacs law of temperature.
• Combined gas law.
• Ideal gas law.
• Avogadros hypothesis.
• Daltons law of partial pressure.
• Grahams law of effusion.

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Boyles law for pressure

• For a given mass of gas at a constant temperature
  the volume varies inversely with pressure
• P1 x V1 P2 x V2

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Boyles law for pressure
Pressure100kPa Volume1.0 L
Pressure200kPa Volume0.5 L
Pressure50kPa Volume 2.0 L
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Boyles law for pressure
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According to Boyles law

• If pressure doubles volume will do what?
• If volume quadruples then pressure is divided by?

Volume will be divided in half.
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Charles law for Temperature

• The Volume of a fixed mass of gas is directly
  proportional to its Kelvin temperature if the
  pressure is kept constant.
• V1 / T1 V2 / T2

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Charles law for Temperature
Pressure100 kPa Volume20 L Temperature200 K
Pressure100 kPa Volume5 L Temperature50 K
Pressure100 kPa Volume10 L Temperature100 K
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Charles law for Temperature
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According to Charles law

• If temperature is doubled then volume does what?
• If Volume triples then pressure does what?

Volume doubles
PSYCH! Nothing.
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Gay-Lussacs law of temperature

• The pressure of a gas is directly proportional to
  the Kelvin temperature if the volume remains
  constant.
• P1 / T1 P2 / T2

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Gay-Lussacs law of temperature
Pressure200 kPa
Pressure100 kPa
Pressure50
Volume10 L
Volume10 L
Volume10 L
Temperature400 K
Temperature100 K
Temperature200 K
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According to Gay Lussacs law

• If pressure triples then temperature does what?
• If the temperature stays constant can the
  pressure go up?

Temperature triples
Hell naw it cant
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Combined gas law

• A combination of Gay-Lussacs law, Charles law
  Boyles law.
• No need to remember all 3 separately.
• (P1 x V1)/T1 (P2 x V2)/T2
• Any part can be canceled out to make the other
  laws

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Ideal gas law.

• Adds fourth variable to Combined gas law.
• Moles (n), take in to account the size of gas
  particles.
• (P1 x V1)/(T1 x n1) (P2 x V2 )/(T2 x n2)

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Ideal gas law questions

• !Double worth!
• Show how you can make the ideal gas law equation
  turn in to any of the preceding equations.

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Avogadros Hypothesis

• Equal volumes of gases at the same temperature
  and pressure contain equal numbers of particles.

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Avogadros Hypothesis
Pressure, temperature, and volume is same for
both.
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Avogadros hypotheses questions

• What is Avogadros hypothesis?
• How many particles were shown on the last fame?

• Equal volumes of gases at the same temperature
  and pressure contain equal numbers of particles.

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Grahams law of effusion

• The rate of effusion for a gas is inversely
  proportionate to the square root of the gases
  molar mass.
• Diffusion the tendency of molecules to move
  towards areas of lower concentration until
  equilibrium is reached.
• Effusion gas escaping through a tiny hole.
• Rate A sqr root of molar mass B
• Rate B sqr root of molar mass A

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Diffusion
Effusion
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Grahams law questions

• What is diffusion?
• What is effusion
• A gass rate of effusion is ________
  proportionate to its __________.

• the tendency of molecules to move towards areas
  of lower concentration until equilibrium is
  reached.

gas escaping through a tiny hole.
Inversely
Molar mass
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K.THNX.CLAP.