The Gas LawsThe Gas Laws

And what they can do for me!And what they can do for me!

=D=D

Put Simply.Put Simply.

The gas laws are a series of rules The gas laws are a series of rules and equations used to determine and equations used to determine

how a gas will react to various how a gas will react to various changes in its established situation.changes in its established situation.

Put simply-erPut simply-er

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

happens.happens.

Here is what will be Here is what will be covered…covered…

Boyle’s law for pressure.Boyle’s law for pressure.Charle’s law for temperature.Charle’s law for temperature.Gay Lussac’s law of temperature.Gay Lussac’s law of temperature.Combined gas law.Combined gas law. Ideal gas law.Ideal gas law.Avogadro’s hypothesis.Avogadro’s hypothesis.Dalton’s law of partial pressure.Dalton’s law of partial pressure.Graham’s law of effusion.Graham’s law of effusion.

Boyle’s law for pressureBoyle’s law for pressure

For a given mass of gas at a constant For a given mass of gas at a constant temperature the volume varies temperature the volume varies inversely with pressureinversely with pressure

PP1 1 x Vx V1 1 = P= P22 x V x V22

Boyle’s law for pressureBoyle’s law for pressure

Pressure=100kPaVolume=1.0 L

Pressure=50kPaVolume= 2.0 L

Pressure=200kPaVolume=0.5 L

Boyle’s law for pressureBoyle’s law for pressure

According to Boyle’s law… According to Boyle’s law…

If pressure doubles volume will do If pressure doubles volume will do what?what?

If volume quadruples then pressure If volume quadruples then pressure is divided by?is divided by?

Volume will be divided in half.

4

Charles’ law for TemperatureCharles’ law for Temperature

The Volume of a fixed mass of gas is The Volume of a fixed mass of gas is directly proportional to its Kelvin directly proportional to its Kelvin temperature if the pressure is kept temperature if the pressure is kept constant.constant.

VV11 / T / T11 = V = V22 / T / T22

Charles’ law for TemperatureCharles’ law for Temperature

Pressure=100 kPaVolume=5 LTemperature=50 K

Pressure=100 kPaVolume=10 LTemperature=100 K

Pressure=100 kPaVolume=20 LTemperature=200 K

Charles’ law for TemperatureCharles’ law for Temperature

According to Charles’ lawAccording to Charles’ law

If temperature is doubled then If temperature is doubled then volume does what?volume does what?

If Volume triples then pressure does If Volume triples then pressure does what?what?

Volume doubles

PSYCH! Nothing.

Gay-Lussac’s law of Gay-Lussac’s law of temperaturetemperature

The pressure of a gas is directly The pressure of a gas is directly proportional to the Kelvin proportional to the Kelvin temperature if the volume remains temperature if the volume remains constant.constant.

PP1 1 / T/ T11 = P = P2 2 / T/ T22

Gay-Lussac’s law of Gay-Lussac’s law of temperaturetemperature

Pressure=100 kPaPressure=50Volume=10 L Volume=10

L

Volume=10 LPressure=200 kPa

Temperature=100 K Temperature=200 K Temperature=400 K

According to Gay Lussac’s According to Gay Lussac’s law…law…

If pressure triples then temperature If pressure triples then temperature does what?does what?

If the temperature stays constant If the temperature stays constant can the pressure go up?can the pressure go up?

Temperature triples

Hell naw it can’t

Combined gas lawCombined gas law

A combination of Gay-Lussac’s law, A combination of Gay-Lussac’s law, Charles’ law & Boyle’s law.Charles’ law & Boyle’s law.

No need to remember all 3 No need to remember all 3 separately.separately.

(P(P11 x V x V11)/T)/T11 = (P = (P22 x V x V22)/T)/T22

Any part can be canceled out to Any part can be canceled out to make the other lawsmake the other laws

Ideal gas law.Ideal gas law.

Adds fourth variable to Combined Adds fourth variable to Combined gas law.gas law.

Moles (n), take in to account the size Moles (n), take in to account the size of gas particles.of gas particles.

(P(P11 x V x V11)/(T)/(T1 1 x nx n11) = (P) = (P22 x V x V2 2 )/(T)/(T2 2 x nx n22) )

Ideal gas law questionsIdeal gas law questions

!Double worth!!Double worth!Show how you can make the ideal Show how you can make the ideal

gas law equation turn in to any of the gas law equation turn in to any of the preceding equations.preceding equations.

Avogadro’s HypothesisAvogadro’s Hypothesis

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

Avogadro’s HypothesisAvogadro’s HypothesisPressure, temperature, and volume is same for both.

Avogadro’s hypotheses Avogadro’s hypotheses questionsquestions

What is Avogadro’s hypothesis?What is Avogadro’s hypothesis?

How many particles were shown on How many particles were shown on the last fame?the last fame?

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

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Graham’s law of effusionGraham’s law of effusion

The rate of effusion for a gas is inversely The rate of effusion for a gas is inversely proportionate to the square root of the proportionate to the square root of the gases molar mass.gases molar mass.

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

Effusion= gas escaping through a tiny hole.Effusion= gas escaping through a tiny hole.

Rate Rate AA = = sqr root of sqr root of molar mass molar mass BB

Rate Rate BB sqr root ofsqr root of molar mass molar mass AA

Diffusion

Effusion

Graham’s law questionsGraham’s law questions

What is diffusion?What is diffusion?

What is effusionWhat is effusion

A gas’s rate of effusion is ________ A gas’s rate of effusion is ________ proportionate to its __________.proportionate to its __________.

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

gas escaping through a tiny hole.gas escaping through a tiny hole.

InverselyMolar mass

K.THNX.CLAP.K.THNX.CLAP.