ch 5

Question 1

density equation

Answer 1

D= PM/RT

Question 2

total pressure equation given partial

Answer 2

Ptotal= PA + PB +…

Question 3

equation for pressure

Answer 3

pressure=force/area

small areas-higher P
larger areas-lower P

Question 4

barometer

Answer 4

measures P of atm

Question 5

more collisions (force) means

Answer 5

higher pressure

Question 6

converting mmHg/torr to atm and kPa

Answer 6

1 atm= 760 mmHg/torr
1 atm= 101.3 kPa

Question 7

combined gas law

Answer 7

P1V1/n1T1 = P2V2/n2T2

must be in K
must be in atm

Question 8

what is R

Answer 8

.08206

Question 9

boyles law

Answer 9

P1V1=P2V2
V/1:1/P
Volume and pressure are indirectly proportionate
BECAUSE
when volume decreases, gas particles collide more often, increasing force, and increasing pressure

Question 10

Charles’ law

Answer 10

relationship between V and T is directly proportional

V1/T1=V2/T2
must be in K

Question 11

Avogadro’s Law

Answer 11

relationship between volume and amount in moles directly proportional

V1/n1=V2/n2

Question 12

ideal gas law

Answer 12

PV=nRT
just combines Boyle, Charles, and Avogadro’s Laws

Question 13

higher molar mass means… ____density

Answer 13

increasing molar mass increases density
PM/RT=D

Question 14

how to find molar mass of a gas

Answer 14

1. measure mass and volume under conditions of known temp and P
2. using ideal gas law, find number of moles
3. calculate molar mass by dividing mass by number moles

Question 15

mole fraction

Answer 15

nA/ntotal= Xa

Xa + Xb + Xc +….= ALWAYS 1

Question 16

equation to find Ptotal given partial pressures

Answer 16

Ptotal= (na + nb + nc +…)(RT/V)
under same temp and volume conditions

Question 17

equation to find partial pressure given either mole fraction or total pressure

Answer 17

Pa=Xa(Ptotal)

Xa is mole fraction (moles/total moles)

Question 18

equation of KE
KMT

Answer 18

KE= 1/2mv^2

m=mass (kg)
v=velocity (m/s)
KE=kinetic energy (J)

Question 19

at a given temp, all gases have…

Answer 19

the same average KE

Question 20

ideal gas conditions

Answer 20

PLIGHT
low pressure
high temp

-assume ideal gas at STP
-lower volume

Question 21

molar volume

Answer 21

m^3/mol

as P in, molar volume decreases

Question 22

IFA increase effect on gas
-temp
-pressure
-ideal?

Answer 22

-IFA increases as temp decreases
-pressure de as IFA inc (less collisions)
-more ideally because lower pressure

Question 23

PV/RT =1 vs not =1
what about >1 and <1?

Answer 23

PV/RT= 1 means ideal
PV/RT not =1 means real/nonideal

PV/RT >1 = particle volume is predominating ideal behavior
PV/RT <1 = IFAs predominate ideal behavior (low pressure)

Question 24

if PV/RT=n=1 then…

Answer 24

IDEAL GAS!

Question 25

relationship between temp and speed

Answer 25

temp=avg KE
avg KE : speed
so
as temp increases, diversity of speed increases (wider distribution of particle speeds)

Question 26

relationship between particle size and speed

Answer 26

the smaller the particles, the wider the distribution of speeds

larger mass=slower particles so more narrow dis of speed