Flashcards in Gas Phase Deck (21):

0

## STP

###
273.15 K

1 atm = 760 mm Hg = 760 torr

Not to be confused with standard state!

1

## Ideal Gas

### Volume-less gas with no intermolecular forces used in calculations that behaves according to the kinetic molecular theory of gases as described by the ideal gas law.

2

## What are the assumptions inherent in the Kinetic Molecular Theory of Gases?

###
• Volume-less particles

• Constant, random motion

• No intermolecular attractions

• Perfectly elastic collisions

• Average kinetic energy proportional to absolute temperature of gas

3

## Ideal Gas Law

### PV = nRT

4

## Boyle's Law

###
Pressure is inversely proportional to Volume at constant Temperature.

PV = k

5

## Gas Constant

###
8.21 X 10^-2 (L•atm)/(mol•K)

8.34 J/(K•mol)

6

## Charles and Gay-Lussac's Law

###
Volume is directly proportional to its Temperature at a constant Pressure.

V/T = k

7

##
Avogadro's Principle

###
The number of moles present is directly proportional to the Volume of the gas at constant Temperature and Pressure. One mole of gas has a volume of 22.4 L.

n/V = k

8

## How does the behavior of Real Gases differ from that of Ideal Gases as Pressure increases to condensation pressure?

### As the pressure increases, particles are pushed closer together and intermolecular forces become stronger as the gas becomes a liquid.

9

## At moderately high pressures (a few hundred atm), what happens to a real gas?

### The volume will be less than that expected from the ideal gas law.

10

## What happens to the Volume of a real gas at extreme pressures?

### The molecules begin to expand, increasing the volume.

11

## What happens to real gases as temperature decreases?

### The average velocity decreases, leading to a smaller Volume, as the Temperature approaches the condensation point and intermolecular forces become stronger, forming a liquid.

12

## Van der Waald equation

###
(P + ((a*n^2)/V^2))(V - nb) = nRT

a corrects for the attractive component

b corrects for the volume

13

## Vapor Pressure

### A vapor's partial pressure when in equilibrium with its liquid and solid state.

14

## Partial Pressure or Dalton's Law of Partial Pressures

###
(Pressure of single gas) = (Total Pressure) (mole fraction of single gas)

mole fraction = (number of moles of gas)/(total number of moles)

Sum of partial pressures equals total pressures

15

## Henry's Law

### Dissolved gas pressure is directly proportional to gas partial pressure above solution.

16

## Average speed of gases

### |v| = (3RT/MM)^1/2

17

## Kinetic Energy and Temperature of gas

### KE = (1/2)mv^2 = (3/2)(Boltzmann's Constant) T

18

## Graham's Law

###
R1/R2 = (MM2/MM1)^1/2

For effusion and diffusion

19

## Diffusion

### Passive transport through a medium due to random motion.

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