Chapter 6

Question 1

SI unit for pressure

Answer 1

Pascal(PA) N/m^2 or j/m^3

Question 2

bar and Pa conversion

Answer 2

1 bar=1•10^5 Pa

Question 3

atm to bars and Pa

Answer 3

1atm=101,325 Pa=1.01325 bar

Question 4

atm to mm Hg and torr

Answer 4

1atm=760 mm Hg=760 torr

Question 5

Forces that affect barometers

Answer 5

gravity and atmospheric pressure

Question 6

Manometer

Answer 6

used to measure pressure of a gas by opening and closing a valve separating the sample gas and mercury pushed down by the Patm. closed end measures gases less than Patm and open end measures gases more than Patm

Question 7

Boyle’s law

Answer 7

P=1\V, P1V1=P2V2

Question 8

Charle’s law

Answer 8

V1/T1=V2\T2, density decreases as temp increases

Question 9

Avogadro’s law

Answer 9

V1/n1=V2/n2

Question 10

Amonton’s\Gay-Lussac’s law

Answer 10

P1\T1=P2\T2

Question 11

Change of state when amount of gas changes equation

Answer 11

P1V1/(n1T1)=P2V2/(n2T2)

Question 12

Change of state with fixed amount of gas equation

Answer 12

P1V1/T1=P2V2/T2

Question 13

Molar volume

Answer 13

volume occupied by one mole of a gas at STP

Question 14

Density of a gas

Answer 14

d=m/v=PM/RT with p in atm and d in g/L

Question 15

what does buoyancy depend on

Answer 15

molar masses and temperature

Question 16

Density formula

Answer 16

d=(molar mass)p/RT

Question 17

Concentration formula

Answer 17

c=n/v=p/RT

Question 18

Molar mass formuls

Answer 18

molar mass=mRT/PV=dRT/P

Question 19

mole fraction

Answer 19

xi=ni/ntotal

add up to 1

Question 20

Kinetic molecular theory

Answer 20

Assumed that gas molecules

1. Have tiny volumes compared with the collective volume they occupy
2. Move constantly and randomly
3. Have average kinetic energy proportional to absolute temp.
4. Engage in elastic collisions with walls of container and other gas molecules
5. Act independently of other gas molecules

Question 21

Root mean square speed of molecules

Answer 21

u=_/(3RT/M)

Question 22

Effusion

Answer 22

the process by which a gas escapes from a container through a tiny hole into a region of lower pressure

Question 23

Graham’s law of effusion

Answer 23

rate of effusion=1/square root of molar mass, applicable when the diameter of the hole is substantially smaller than the average distance that a gaseous particle travels between collisions

Question 24

Diffusion

Answer 24

spread of one substance through another

Question 25

How do gas particles act at higher pressures vs STP?

Answer 25

At high P and low V, Vgas is not negligible, and attractive forces between gas molecules are significant

Question 26

Van der Waals equation

Answer 26

P=nRt/(V-nb) - an^2/V^2

Question 27

What is the purpose of a and b in van der Waal’s equation?

Answer 27

a: corrects for attractive forces that affect pressure
b: corrects for volume occupied by molecules