Temperature And Phases Of Matter Flashcards
Temperature and pressure are
Proportional
By changing temperature and pressure it is possible to get solid, liquid and gas at the same time. This is called the….
Triple point
A phase diagram has … on the y axis and … on the x axis
Pressure against temperature
By increasing the pressure of water you can
Get from water vapour to water provided that temperature is greater or equal to waters triple point
What’s water triple point
0.01•C at a pressure of 0.61kPa
Temperature is
A measure of how things are hot or cold
How hot or cold an object is related to
Kinetic energy
What are the 2 points that the Absolute scale is based on
Absolute zero and the triple point of water because both of these fixed no matter where you are in the universe
What’s the triple point of water in degrees
0.01•C
What’s the triple point of water in kelvin
273.16K
Define heating
The transfer of energy from a region of higher temperature to one at a lower temperature.
Object A has a higher temperature than object B. Object A and object B are touching. Describe the way object B is heated.
Object B is heated by object A. Object A is heating object B
If body A is in thermal equilibrium with body B and body B is also in thermal equilibrium with body C. Then…
Body A and body C must be in thermal equilibrium with each other and all the bodies will have the same temperature
The phases of matter are
Solid
Liquid
Gas
What are the two points that the degree Celsius is based on
The freezing point of water and the boiling point of water at 1 atmospheric pressure
Define the triple point
A specific temperature and pressure where the 3 phases of matter can exist in thermal equilibrium.
The kinetic model describes
How all substances are made up of atoms or molecules. Which are arranged differently depending non the phase of the substance
Using the kinetic model, how are atoms or molecules are arranged in solids
In solids the atoms or molecules are regularly arranged and packed closely together with strong electrostatic forces of attraction between them holding them in fixed positions, but they can still vibrate so have still some kinetic energy.
Using the kinetic model, how atoms or molecules arranged in liquids ?
In liquids the atoms or molecules are still very close together but they have more kinetic energy than in solids. They can also change position and flow past each other.
Using the kinetic model, how are atoms or molecules arranged in gases
In gases the atoms or molecules have more kinetic energy than those in liquid and they are further apart. They are free to move past each other as there are negligible electrostatic forces between them, unless they collide with each other or the walls of the container. They move randomly with different speeds in different directions
Describe what happens when a solid is heated.
When a solid is heated, the particles gain more energy and vibrate more vigorously. Eventually they may break away from the solid structure and become free to move around, meaning it has turned into a liquid.
Describe what happens when a liquid is heated.
When a liquid is heated, some of the particles gain enough energy to break away from other particles. The particles which escapes from the body of the liquid become a gas
Why is ice less dense than water?
Because the particles in a solid arrangement are held slightly further apart than the particles in their random arrangement in liquid water
Define the internal energy
the sum of the randomly distributed electrostatic kinetic and potential energies of atoms or molecules within the substance.
A gas has an internal energy of 100J and a mass of 3g. What’s the kinetic energy of its particles?
100J .
this is because the electrostatic forces in a gas are negligible unless when particles are colliding, hence the potential energy will be 0J. From there using the formula relating internal energy, electrostatic kinetic and potential energies, we can deduce that the kinetic energy must be equal to the internal energy.
If two objects are said to experienced a gravitational force, they are said to have a gravitational potential energy. If two objects are said to experience an electrostatic attraction/force, then they are said to have…
an electrostatic potential energy
When a substance change phase the temperature…
does not change, nor does the kinetic energy of the particles, but the electrostatic potential energy does change significantly
In different phases of matter, the electrostatic potential energies have…
different values
The electrostatic potential energy in gases is
0
The electrostatic potential energy in liquids is
a negative value, where the negative sign means that energy must be supplied to break the atomic or molecular bonds
The electrostatic potential energy in solids is
a large negative value, where the negative sign means that energy must be supplied to break the atomic or molecular bonds
state the phases of matter in descending order based on their electrostatic potential energy
gases - 0J
liquids - (-ve) J
solids - (-ve) J
How can u test for the specific heat capacity of a substance?
By using the specific heat capacity equation and substituting E with E=(It)V, where V and I are got from reading an ammeter and voltmeter of a circuit that supplies a stable current to heat an object via a heater.
A substance is cooled until it reaches -273.15*C. Identify all the statements below which accurately describe the energy of the substance.
A Its internal energy is not at its minimum value.
B Its internal energy is at its non-zero minimum value.
C Its internal energy is at its minimum value of zero.
D Its particles’ kinetic energy is zero.
E Its particles’ potential energy is zero.
F The substance is at absolute zero.
G The substance can be cooled further.
B, D, F.
Why will a substance at absolute zero still have a non zero internal energy?
Because the electrostatic potential energy is unaffected by the change in temperatures.
Can the internal energy of an object decrease further if the object has a temperature of absolute zero?
No because the kinetic energy will be 0 and the electrostatic potential energy will not change unless a change of state/phase occurs, which cannot occur at or below absolute zero, as the absolute zero is the lowest temperature possible in the universe.
Can the electrostatic potential energy of an object decrease further if the object has a temperature of absolute zero?
No because the electrostatic potential energy will not change unless a change of state/phase occurs, which cannot occur at or below absolute zero, as the absolute zero is the lowest temperature possible in the universe.
The specific heat capacity of water is 4181Jkg^{-1}K^{-1}. What does the word ‘specific’ mean?
per unit mass
Define specific latent heat
Specific latent heat capacity is the energy required per unit mass to change the phase of a substance, while at constant temperature.
the specific capacity is independent of the…
mass
Explain what happens when 2 substances in contact have different temperatures.
If two substances are in contact, and one is hotter than the other, then there will be a net flow of thermal energy from the hotter object to the cooler object. The hotter object will cool down and the cooler one will warm up, until they are at the same temperature, where there will be no net energy transfer. Two objects are in thermal equilibrium when there is no net transfer of thermal energy between them.
Describe how this graph leads to the concept of an absolute zero of temperature.
Idea of extrapolating graph back (to negative temperatures)
Volume is zero at absolute zero / negative volumes are impossible
Fig. 6.1 shows the apparatus used to observe Brownian motion using pollen grains suspended in a liquid.
State two conclusions that may be deduced about the molecules of the liquid from the motion of the pollen grains observed with the microscope.
Molecules (of the liquid) are in random/haphazard motion (AW)
Molecules (of liquid) are smaller than pollen grains
