Quiz According to the kinetic theory of gases… What is the formula for Boyle’s Law?

The student will be able to: Explore mixtures and movements of gases in

order to relate total pressure to partial pressure and explain gas diffuses and effuses.

An ideal gas is made up of gas particles that…

a. Have a high massb. Are in random motionc. Have volumed. Can be liquefiede. Attract each other

GasesMixtures and Movements

Gases: Mixtures and Movements• A list of gear for an

expedition to Mount Everest includes climbing equipment, ski goggles, a down parka with a hood, and most importantly compressed-gas cylinders of oxygen. You will find out why a supply of oxygen is essential at higher altitudes.

The contribution each gas in a mixture makes to the total pressure is called the partial pressure exerted by that gas.

Dalton’s Law

 In a mixture of gases, the total pressure is the

sum of the partial pressures of the gases.

Dalton’s Law

Dalton’s law of partial pressures states that, at constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the component gases.

Dalton’s Law

Dalton’s LawAnimation 17 Observe the behavior of a mixture of

nonreacting gases.

Three gases are combined in container T.

Dalton’s LawThe partial pressure of oxygen must be 10.67

kPa or higher to support respiration in humans. The climber below needs an oxygen mask and a cylinder of compressed oxygen to survive.

Sample Problem

Sample Problem

Sample Problem

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Graham’s LawDiffusion is the tendency of. molecules to

move toward areas of lower concentration until the concentration is uniform throughout.

Bromine vapor is diffusing upward through the air in a graduated cylinder.

Graham’s LawAfter several

hours, the bromine has diffused almost to the top of the cylinder.

Graham’s LawDuring effusion, a gas escapes through a

tiny hole in its container.

Gases of lower molar mass diffuse and effuse faster than gases of higher molar mass.

Graham’s LawThomas Graham’s Contribution

Graham’s law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of the gas’s molar mass. This law can also be applied to the diffusion of gases.

Graham’s LawComparing Effusion Rates

A helium filled balloon will deflate sooner than an air-filled balloon.

Helium atoms are less massive than oxygen or nitrogen molecules. So the molecules in air move more slowly than helium atoms with the same kinetic energy.

Graham’s LawBecause the rate of effusion is related only to a

particle’s speed, Graham’s law can be written as follows for two gases, A and B.

Graham’s LawHelium effuses (and diffuses) nearly three

times faster than nitrogen at the same temperature.

Graham’s LawAnimation 18 Observe the processes of gas effusion and

diffusion.

Practice!1. What is the partial pressure of oxygen in a

diving tank containing oxygen and helium if the total pressure is 800 kPa and the partial pressure of helium is 600 kPa?

a. 200 kPab. 0.75 kPac. 1.40 104 kPad. 1.33 kPa

Practice!2. A mixture of three gases exerts a pressure of

448 kPa, and the gases are present in the mole ratio 1 : 2 : 5. What are the individual gas pressures?

a. 44 kPa, 88 kPa, and 316 kPab. 52 kPa, 104 kPa, and 292 kPac. 56 kPa, 112 kPa, and 280 kPad. 84 kPa, 168 kPa, and 196 kPa

Practice!3. Choose the correct words for the spaces.

Graham's Law says that the rate of diffusion of a gas is __________ proportional to the square root of its _________ mass.

a. directly, atomicb. inversely, atomicc. inversely, molard. directly, molar

Small Scale-LabPurpose:

To infer diffuse of a gas by observing color changes during chemical reactions.

Be sure to wear :Safety gogglesLab apronGloves

(20 min)

Analysis questions 1-4

(20 MIN)

1. Did we accomplish the objective? Explain.2. Compare and Contrast Partial pressure to

total pressure.3. Compare and contrast Diffusion to

Effusion.4. Explain the purpose or objective of the

Small Scale-Lab5. Was there anything from the lab that

surprised you? Were you already aware that gases can turn certain chemical colors?

Dalton’s Law and Graham’s Law worksheet

Final ExamReview Packet Questions 16-18