The Gas Phase

Question 1

Ideal Gas

Answer 1

Theoretical gas whose molecules occupy negligible space and whose collisions are perfectly elastic. Gases behave ideally under reasonably high temperatures and low pressures

Question 2

STP

Answer 2

273 K (0C), 1 atm

Question 3

1 mol Gas

Answer 3

At STP 1 mol of gas = 22.4 L

Question 4

Units

Answer 4

1 atm = 760 mmHg = 760 torr = 101.3 kPa = 14.7 psi

Question 5

Real gases deviate from ideal behavior at…

Answer 5

low temperatures and high pressure

Question 6

At moderately high pressure, low volume, or low temperature…

Answer 6

Real gases will occupy less volume than predicted by the ideal gas law because the particles have intermolecular attractions.

Question 7

At extremely high pressure, low volume, or low temperature…

Answer 7

Real gases will occupy more volume than predicted by the ideal gas law because the particles occupy physical space.

Question 8

Van der Waals Equation of State

Answer 8

(p + n^2a/V^2)(V-nb) = nRT

Question 9

Ideal Gas Law

Answer 9

PV = nRT
R = 8.314 J/molK

Question 10

Density of Gas

Answer 10

p= m/v = PM/RT

Question 11

Combined Gas Law

Answer 11

P1V1 / T1 = P2V2 / T2

Question 12

Avogadro’s Principle

Answer 12

n/v = k or n1/v1 = n2/v2

Question 13

Boyle’s Law

Answer 13

PV = k or P1V1 = P2V2

Question 14

Charles’s Law

Answer 14

V/T = k

Question 15

Gay-Lussac’s Law

Answer 15

P/T = k

Question 16

Dalton’s Law (total pressure from partial pressures)

Answer 16

PT = PA + PB + PC…

Question 17

Dalton’s Law (partial pressure from total pressure)

Answer 17

PA = XAPT

Question 18

Henry’s Law

Answer 18

[A] = kH x PA

Question 19

Average Kinetic Energy of a Gas

Answer 19

KE = 1/2 m v^2 = 3/2 KB T

Question 20

Root-Mean-Square Speed

Answer 20

urms = sqrt 3RT/M

Question 21

Diffusion

Answer 21

The spreading out of particles from [high]–>[low]

Question 22

Effusion

Answer 22

The movement of gas from one compartment to another through a small opening under pressure

Question 23

Graham’s Law

Answer 23

r1/r2 = sqrt M2/M1

Question 24

Low molar mass

Answer 24

diffuse/effuse FASTER

Question 25

High molar mass

Answer 25

diffuse/effuse slower

Question 26

Diatomic Gases

Answer 26

Exist as diatomic molecules, never a stand-alone atom. Includes H2, N2, O2, F2, Cl2, Br2, and I2.
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