# Gases

## 25 terms · Chapter 5 Terms

### Millimeters Mercury

The common unit of pressure, symbolized mm Hg

### Atmosphere

a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade

### bar

a unit of pressure that is nearly, but not quite equal to an atmosphere; 1.013bar = 1atm = 760mm Hg

### Ideal Gas Law

Volume is directly proportional to amount. Volume is directly proportional to absolute temperature.Volume is inversly proportional to pressure.

PV=nRT

### R

Gas constant; 0.0821 (L atm/ mol K), 8.31 (J/ mol K), 8.31x10³ (g m²/ s² mol K)

### STP

standard temperature and pressure; EX: At STP, one mole of gas occupies 22.4 L.

### Vapor Pressure

the pressure exerted by a vapor over a liquid

### Mole Fraction

The ratio of the moles of the substance to the total moles.

### Partial Pressure

the pressure of each gas in a mixture

### Effusion

passage of a gas through a small hole

### Combined Gas Law

P₁V₁/ T₁ = P₂V₂/ T₂

### Boyle

held temperature constant; Equation: P₁V₁ = P₂V₂ (Chickens Go Bawk)

### Charles

held pressure constant; Equation: V₁/ T₁ = V₂/ T₂ (Chickens Go Bawk)

### Gay-Lussac

held volume constant; Equation: P₁/ T₁ = P₂/ V₂ (Chickens Go Bawk)

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

### Diffusion

the spreading of a gas through a room.

### Dalton's Law

the total pressure is equal to the sum of its parts.

### Graham's Law

velocity of gas varies inversley with mass.

### Kinetic Theory

the theory that gases are made up of a large sum of small particles.

### Vapor

the gaseous form of any substance

### Velocity

the distance traveled per unit time

### Manometer

a pressure gauge for comparing pressures of a gas

### Barometer

an instrument that measures atmospheric pressure

### Kinetic Molecular Theory

-KE is directly proportional to the absolute temperature. -The volume of s gas particle is negligible relative to the volume in which the gas is contained. -Attractive and repulsive forces between gas molecules are negligible. -Gases consist of atoms or molecules in constant, random motion. -At a given temperature, all gases will have the same average KE. -Collisions between gas particles and their container are elastic.

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