Ch 8: The Gas Phase

Question 1

gas systems are described by

Answer 1

temperature, pressure, volume, and number of moles (n)

Question 2

pressure equiv include 1 atm =

Answer 2

760 mmHg
760 torr
101.325 kPa

Question 3

simple mercury barometer

Answer 3

measures incident (usually atmospheric) pressure.

as pressure increases, more mercury is forced into the column, increasing its height

as pressure decreases, mercury flows out of the column under its own weight, decreasing its height

Question 4

standard temperature and pressure for ideal gases (STP)

Answer 4

273 K (0C) and 1 atm

Question 5

at STP one mole of an ideal gas occupies

Answer 5

22.4 L

Question 6

ideal gas law

Answer 6

describes the relationship between four variables of the gas state for an ideal gas

Question 7

Avogadro’s principle

Answer 7

special case of the ideal gas law for which the pressure and temperature are held constant; shows direct relationship between the number of moles of gas and volume

Question 8

Boyle’s Law

Answer 8

special case of the ideal gas law for which temperature and number of moles are held constant; it shows a direct relationship between the number of moles of gas and volume

Question 9

Charles’s Law

Answer 9

special case of ideal gas law for which pressure and number of moles are held constant; shows direct relationship between temperature and volume

Question 10

Gay-Lussac’s Law

Answer 10

special case of the ideal gas law for which volume and number of moles are held constant; it shows direct relationship between temperature and pressure

Question 11

combined gas law

Answer 11

combo of boyle, charles, gay-lussac

shows inverse relationship btwn pressure and volume along with direct relationships btwn pressure and volume with temperature

Question 12

Dalton’s Law of partial pressures

Answer 12

states that individual gas components of a mixture of gases will exert individual pressures in proportion to their MOLE FRACTIONS

total pressure of a mixture of gases to the sum of the partial pressures of the component gases

Question 13

Henry’s Law

Answer 13

amount of gas dissolved in solution is directly proportional to the partial pressure of that gas at the surface of a solution

Question 14

kinetic molecular theory

Answer 14

attempt to explain the behavior of gas particles; makes a number of assumptions about the gas particles like…

negligible volume
do no have intermolecular attractions or repulsions
undergo random collisions with each other and the walls of the container
collisions are elastic
average kinetic energy is directly prop to temp

Question 15

Graham’s Law

Answer 15

behavior of gas diffusion or effusion, stating that gases with lower molar masses will diffuse or effuse faster then gases with higher molecular masses at same temperature

Question 16

diffusion

Answer 16

spreading out of particles from high to low concentrations

Question 17

effusion

Answer 17

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

Question 18

real gases deviate from ideal behavior under __ (low volume) and ____ conditions

Answer 18

high pressure

low temperatures

Question 19

real gases will occupy less volume than ideal in _______ because the particles have intermolecular attractions

Answer 19

moderate high pressure, low volume, or low temp

Question 20

real gases will occupy more volume than ideal in ____ bc particles occupy space

Answer 20

extremely high pressure, low volume, or low temp

corrected with van der waals equation of state with a and b

Question 21

van der waals equation of state a is ____ b is ____

Answer 21

intermolecular attractions

molecular volume