7d Flashcards

1
Q

what does <v> mean</v>

A

its the average molecule speed ( in regards to cartesian coordinates )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does <v> equal to in terms of v's</v>

A

<v> = Vx2 + Vy2 + Vz2
</v>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when at atom moves in any direction,, is movement in each axis equal

A

yesss
the motion in any direction aka x, y , z is equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

if motion in any direction is equal,, what does the equation for v’s equal

A

Vx2 = Vy2 = Vz2 = <v>2 / 3</v>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

on average,, what proportion of the molecules collide with a wall + what does this do

A

on average 1/2 of the molecules will collide with the wall.

across an area of ‘A’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when ur moving along the x axis and colliding with a wall of area ‘ A ‘,, force on a wall due to momentum change is what

A

F = 🔺Px / 🔺T

= (2mvx 🔺xA / 🔺t ) n/2

= mVx 🔺x An / (🔺x/Vx)

= mVx^2 nA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

okay so we have 2 lines paralel to each other,, with both of them pointing up,, what are the lines labelled as,, and what is the difference between the 2 lines,, and what is the image that completes it

A

okay so the lines are labelled as A ( the one that that gas particle is colliding with)

the difference between the 2 lines is 🔺x.

the bit that completes the diagram is a particle with arrows pointing at the ‘A’ line and back off into space between the two lines.

arrow towards the line ‘A’ = mVx

arrpw away from the ‘A’ =
–mVx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

okay so we have the diagram of the gas particle colliding with the ‘A’ line and being bounced back off,, what does the gas particle do to the containers wall

A

the partticle collides with the ‘A’ line

this causes a pressure on the containers wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the gas particle collides with the A line which puts pressure on the containers wall,, what is this pressure related to,,

A

the square of the molecular velocity!!!!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the pressure of the containers wall corresponds to what

A

P = F/A

which is equal to
mVx^2 n

= 1/3 mn<v>^2
= 1/3M N/V <V>^2</V></v>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what can we replace Vx with and what does this give us

A

1/3<v></v>

bc <v> is the sum of all the v's</v>

and theres 3 v’s : x,y,z

so RT = 1/3 M <v>^2</v>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what if we add the boltzman constant to an equation

A

1/2 m <v>^2 = 3/2 KBT</v>

bc M = mNa
and KB = R/Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the average kinetic nergy of a molecule

A

3/2 KBT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the total kinetic energy of 1 mol of a gas

A

3/2 RT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

whats P(v)

A

the probability distribution of molecular velocity, v.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is V

A

velocity vector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the components of velocity

A

vx
vy
vz

18
Q

P(v) dvx, day, dvx is what

A

the molecule fraction whos velocity vector components are in the range

of the original vector + the change in the original vector.

aka point vx + dvx

19
Q

what do we mean when we say boltzman

A

the probabiltiy that a molecule is in a stage of energy, E, is proportional to

exp ( -E / KBT)

20
Q

what is P(E)

A

the number of different states in which the molecule has energy

its called the density of states

21
Q

for a gas at thermal equilirbium, the probability of a molecule having translational kinetic energy =

A

Ekin = 1/2 mv^2

22
Q

v^2 =

A

Vx^2 + vy^2 + Vz^2

this is proportional to exp(-Ekin / KBT )

23
Q

the probability ,, P(V) (aka the probability distribution) can be written assssss

A

1/z exp(-mv^2 / 2KBT)

24
Q

what is Z

A

Z is the normalisation factor

25
Q

whats does Z equal to mathematically

A

exp ( -mv^2 / 2KBT)

26
Q

the integrat of probability distribution from - infinity to infinity is equal to what

A

1

27
Q

what can the normalisation factor be calculated from

A

integral of infinity to - infinity

exp( -mv^2 / 2KBT)

28
Q

1/Z =

A

(m / 2pi KBT) ^3/2

29
Q

the maxwell distribution,,, of the probability distribution is whattttt

A

P(V) = (m/2 pi KBT)^3/2 exp(-mv^2 / 2KBT)

30
Q

from the velocity (vector) distribution what can we do

A

we can obtain the probability distribution of molecular speed, which is the probability of molecular speeds to be in the range of the original + the difference.

31
Q

what is the probability distribution of molecular speeds

A

the probability of a molecules speed to be in its normal speed + the difference in its speed

32
Q

what can we define f(V) as and what is this

A

4 pi P ( V) V^2

this is the probability density for molecular speeds

33
Q

what is beta

A

m / 2KBT

34
Q

what is M equal to

A

mNa

35
Q

what is R equal to

A

KB Na

36
Q

how can we calculate the average speed

A

<v> integral of Vf(v)dv
</v>

37
Q

the average energy of a single molecular can be calculated as what

A

< 1/2 mv^2 > = m4 pi / 2Z

= 3/2 KBT

38
Q

the average speed is directly proportinal toooo

A

the square root of the absolute temp

39
Q

the average speed of a molecule is inversely proportional to what

A

inverself proportional to itss molar mass.

aka heavier the mass,, smaller the speed

40
Q

the average kinetic energy can be directly linked to what

A

the absolute temp

41
Q

the average kinetic energy is independent of what

A

its independent of its mass.

the kinetic energy depends on temp but not the masssss

42
Q

when u plot the probability distribution of molecular velocity against speed!! how does temp affect the plot

A

a lower temp = a larger probabiltiy distribution + smaller speed

a higher temp = smaller probability distribution of molecular velocity,, and a larger range of speed,,, but it also reaches higher speeds.