Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A2 Physics > 3.6.2 - Thermal Physics > Flashcards

3.6.2 - Thermal Physics Flashcards

1
Q

Kelvin =

A

Celcius + 273

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

What happens at 0K?

A

Molecules have zero KE.

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

What is the internal energy of a body?

A

The sum of the randomly distributed kinetic and potential energies of all its particles.

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

What happens to particles as the temperature increases?

A

Average particle speed increases, average KE of particles increases, distribution curve becomes more spread out.

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

Which way is heat always transferred?

A

Hotter substance to cooler substance.

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

How else is heat transferred?

A

By radiation.

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

What is the specific heat capacity of a substance?

A

The amount of energy needed to raise the temperature of 1kg of the substance by 1K.

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

What is the unit for c?

A

Jkg-1K-1

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

How can you measure the change in temperature of a solid?

A

Using an electric heater and digital thermometer inside an insulating material.

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

How can you measure the change in temperature of a liquid?

A

Using a heating coil and digital thermometer all inside an insulating material.

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

What can you use experimentally to find the specific heat capacity of a substance?

A

Using continuous-flow calorimeter.

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

What do you need to record to find the specific heat capacity of a substance using continuous flow calorimeter?

A

The flow rate and duration to find mass. Temperature difference of substance at in and out points. Current and potential difference.

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

What is the equation when using continuous flow calorimeter?

A

Q = mcΔt + H (heat lost to surroundings)

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

When you repeat the experiment what is the overall equation?

A

Q2 - Q1 = cΔt (m2 - m1)

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

What happens when a substance changes state?

A

Its internal energy changes but its KE and temperature stay the same. This is because the potential energy of the particle is constant.

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

What happens on the flat parts of a changing state graph?

A

KE stays the same, potential energy increases as bonds are broken.

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

What is latent heat?

A

The energy needed to break the bonds that hold the particles in place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the specific latent heat of fusion or vaporisation?

A

The quantity of thermal energy needed to be gained or lost to change the state of 1kg of a substance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The change of internal energy of the object =

A

The total energy transfer due to work done and heating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Boyle’s law?

A

At a constant temperature the pressure p and volume V of a gas are inversely proportional.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does Boyle’s law tell us?

A

pV = constant so p1V1 = p2V2

22
Q

Describe the pressure volume graph of an ideal gas.

A

Exponential curve downwards.

23
Q

What is Charles’ law?

A

At constant pressure, the volume V of a gas is directly proportional to its absolute temperature, T.

24
Q

What is an ideal gas?

A

A gas which obeys both Boyle’s law and Charles’ law.

25
Q

What does Charles’ law tell us?

A

V/T - constant so V1/T1 = V2/T2

26
Q

What does Charles’ law graph look like?

A

Straight line through the origin.

27
Q

Explain Charles’ law.

A

When you heat a gas, the particles gain KE and move more quickly. At a constant pressure, this means they move further apart, so the volume of the gas increases.

28
Q

The pressure law?

A

At constant volume, the pressure p of an ideal gas is directly proportional to its absolute temperature T.

29
Q

What is the pressure at absolute zero?

A

Zero

30
Q

What does the pressure law tell us?

A

p/T = constant so p1/T1 = p2/T2

31
Q

What is molecular mass?

A

The sum of all the masses of all the atoms that make up a single molecule.

32
Q

What is Avogadro’s constant?

A

The number of atoms in 12g of carbon 12.

33
Q

What is molar mass?

A

The mass that 1 mole of a substance would have.

34
Q

Number of molecules =

A

Moles x Avogadro’s constant

35
Q

What is the ideal gas equation with R?

A

pV = nRT

36
Q

What is T measured in?

A

Kelvin

37
Q

What is V measured in?

A

m3

38
Q

What does the Boltzmann constant, k, =?

A

R / Na

39
Q

What does nR =

A

Nk

40
Q

What is the ideal gas equation with k?

A

pV = NkT

41
Q

When is work done?

A

When a gas expands or contracts at constant pressure.

42
Q

Work done =

A

pΔV

43
Q

What is Brownian motion?

A

When a particle suspended in fluid has random motion.

44
Q

What did Brownian motion evidence?

A

That the air is made up of tiny atoms or molecules moving really quick - helped the idea that everything is made from atoms.

45
Q

What is constant for ideal gases?

A

pV, V/T, p/T

46
Q

Main assumptions of kinetic theory (10)

A
  • All molecules of a particular gas are equal.
  • Collisions between molecules and walls are elastic.
  • Collisions between molecules and themselves are elastic.
  • Size of actual molecules is negligible compared to molecular separation.
  • Laws of Newtonian mechanics apply.
  • Extremely large number of molecules mean that statistical methods can be applied.
  • Between collisions molecules move in straight lines at constant speed.
  • Motion of molecules is random.
  • Gravitational effects are negligible.
  • Time for each collision is negligible.
47
Q

What is all the internal energy of an ideal gas and what can you use this for?

A

KE - means you can use the product of pV to find total KE.

48
Q

What are empirical laws?

A

Based on observations and evidence, so we can predict that things will happen but they don’t explain why.

49
Q

What is a theory?

A

Based on assumptions and derivations from knowledge and theories we already had.

50
Q

When is a scientific idea accepted?

A

When they can be independently validated.

51
Q

What is validation?

A

The process of repeating an experiment done by someone else, using the theory to make new predictions, and then testing them with new experiments in order to support or refute the theory.

A2 Physics (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions