Kinetic Theory Flashcards
The states of matter:
At any given temperature all substances exist in one of these states of matter
Solid, liquid or gas
How can the differences between solids, liquids and gases be explained
By looking at the particles
What are all substances made up of
Particles
These particles are………to each other, some particles are………………to each other and others…….
The particles are attracted to each other. Some particles are attracted strongly to each other, and others weakly.
What do the particles do
Move around
What type of energy do particles have
Kinetic energy
What happens to the kinetic energy of the particles with temperature
It increases with temperature
Properties of solids
Shape- fixed
Volume - fixed
Particle movement - vibrate from side to side
Forces of attraction between particles - strong
Particle energy - low energy
Examples (at room temperature) - wood, pencil
Properties of liquids
Shape- takes the shape of the container
Volume - fixed
Particle movement - move around each other
Forces of attraction between particles - fairly strong
Particle energy - medium energy
Examples (at room temperature) - Water
Properties of gases
Shape- fills the entire container
Volume - no fixed volume
Particle movement - random in all directions
Forces of attraction between particles - weak
Particle energy - lots of energy
Examples (at room temperature) - air, oxygen, carbon dioxide
Changes of state:
Solid to liquid
Melting
Changes of state:
Liquid to solid
Freezing
Changes of state:
Liquid to gas
Evaporating
Changes of state:
Gas to liquid
Condensing
Some materials will change directly from a gas to a solid without going through the liquid phase e.g. carbon dioxide and iodine. The change of state from a gas directly to a solid is known as what
Sublimation
When does evaporation occur
When the particles in a liquid escape to form a vapour
What temperature can evaporation take place at
At any temperature but it occurs most rapidly at a liquids boiling point
When evaporation occurs why does the temperature of the liquid fall
Because the particles that escape take some energy from the remaining particles
Evaporation is another method of what
Heat transfer
When can you feel a heat change (evaporation)
You can feel an energy change as you stand wet and shivering at the side of a swimming pool. As the liquid on your body evaporates, it takes the energy it needs from your skin and you feel cold.
Not all………..evaporate at the same rate
Liquids
Not all liquids evaporate at the same rate experiment, observations and conclusion:
Liquid- water
Does it feel cool- yes
How quickly does it evaporate from your finger - slowly
Liquid - oil
Does it feel cool - no
How quickly does it evaporate from your finger - it doesn’t cool your finger, you have to wipe it off
Liquid - ethanol
Does it feel cool - yes, it was the coldest
How quickly does it evaporate from your finger - fast
Conclusion - not all liquids evaporate at the same rate
The temperature at which a substance changes from a solid to a liquid is called its what
Melting point (freezing point)
What is the melting point of pure water
0 degrees
The temperature of which a substance changes from a liquid to a gas is called its what
Boiling point
The boiling point of pure water is what
100 degrees
Different materials have different what
Melting and boiling points
A measurement of melting or boiling points can be used to determine what
The properties of a substance
Room temperature is what
20 degrees
A solid has a melting point above what
20 degrees
A liquid has a melting point of what but a boiling point of what
A liquid has a melting point below 20 degrees but a boiling point above 20 degrees
A gas has a melting and boiling point of what
Melting point and boiling point below 20 degrees
What state is water at 25 degrees
Liquid
What state is water at 300 degrees
Gas
What state is water at -100 degrees
Solid
What state is water at 67 degrees
Liquid
What state is water at -25 degrees
Solid
What state is water at 116 degrees
Gas
What state is a substance at room temperature if it melts at 15 degrees and boils at 37 degrees
Liquid
What state is a substance at room temperature if it melts at 70 degrees and boils at 115 degrees
Solid
What state is a substance at room temperature if it melts at -33 degrees and boils at 10 degrees
Gas
What state is a substance at room temperature if it melts at 10 degrees and boils at 18 degrees
Gas
What state is a substance at room temperature if it melts at 189 degrees and boils at 1089 degrees
Solid
What state is a substance at room temperature if it melts at -66 degrees and boils at 66 degrees
liquid
What state is a substance at room temperature if it melts at 0 degrees and boils at 88 degrees
Liquid
What state is a substance at room temperature if it melts at 30 degrees and boils at 230 degrees
Solid
What state is a substance at room temperature if it melts at -125 degrees and boils at 15 degrees
Gas
Studying temperature changes over a period of time ( what happens to a block of ice when you put a Bunsen underneath it): why do plateaus occur
The two flat regions (plateaus) occur because any heat energy put in is used to weaken the forces of attraction between the particles for some time (instead of heating the substance) so the overall temperature of the container does not increase.
Studying temperature changes over a period of time ( what happens to a block of ice when you put a Bunsen underneath it):
Just like heating curves, cooling curves have horizontal flat parts where what happens
Where the state changes from the gas to liquid or from liquid to solid
Studying temperature changes over a period of time ( what happens to a block of ice when you put a Bunsen underneath it):
What happens at the melting and boiling point
The temperature stays the same as energy goes into separating the particles
Why do plateaus in cooling curves occur
Because any heat energy is given out as forces of attraction between the particles is set up, so the overall temp of the container does not decrease
Dissolving and diffusion:
What is a solute
A solids that dissolves in a solvent
Dissolving and diffusion:
What is a solvent
A liquid that dissolves in a solute
Dissolving and diffusion:
What is a solution
The mixture formed when a solute dissolves and mixes fully with a solvent.
Dissolving and diffusion:
Solute + solvent —->
Solution
Dissolving and diffusion:
Eg of solute + solvent —-> solution
Coffee granules + hot water —-> cup of instant coffee
Dissolving and diffusion:
What happens when a solute dissolves
It does not disappear, the particles simply mixes with the particles of the solvent
Dissolving and diffusion:
Is calcium carbonate soluble in water
No because the calcium carbonate and water particles are not able to mix
Dissolving and diffusion:
Is copper sulphate soluble in water
Yes because copper sulphate and water particles are able to interact and mix together
What can mass not be
Created or destroyed, it can only be changed from one form into another
Dissolving and diffusion:
What is diffusion
Diffusion is the random movement of particles, when particles diffuse, they spread out and mix with other particles
Dissolving and diffusion:
Give an example of diffusion
the smell of perfume can be detected by people on the other side of a room because the perfume particles diffuse in the air
What is the second definition of diffusion
Diffusion is the random movement of particles from an area of high concentration to an area of low concentration. The particles mix with other particles.
Why do particles in liquids and gases diffuse easily
Because they are free to move around, however, it is possible for solids to diffuse as well
Diffusion of bromine review
When the cover slip that separates the two gases is removed, the brown gas spreads to fill the two containers easily
Why will particles of a gas diffuse faster
The gas particles are moving around faster than the particles in a liquid because they have more energy. This means that the gas particles will spread out more quickly.
Expansion and contraction:
When we increase a materials temperatures what do we do to its particles
When we increase a material’s temperature, we increase the energy of its particles and the material will expand, regardless of whether it is a solid, a liquid or a gas
Expansion and contraction:
Expansion in solids
COLD - particles are sitting at room temperature and vibrating side by side
HOT - when the solid is heated, the particles vibrate more vigorously and nudge each other out of the way. The structure physically becomes bigger
Expansion and contraction:
Why do solids expand on heating
Solids expand on heating because the more heat energy there is in the solid, the faster its particles will vibrate and they push their neighbours further away.
Expansion and contraction:
Give an example of a problem caused when materials (a bridge) which are expanding and contracting occur
Bridges expand in the summer heat and need special joints to stop them bending out of shape
Expansion and contraction:
What happens to the particles in a liquid when they are heated
They move around each other more and take up more room.
Expansion and contraction:
How does a thermometer work
By expansion and contraction of the liquid inside it
It is important to remember that it is the spaces between the particles that change size during expansion and contraction, the particles remain the same size.
WAS JUST A HELPFUL NOTE
What is the definition of a heating curve
Graph to show temperature changes of a substance on heating
What is the definition of a cooling curve
Graph to show temperature changes of a substance on cooling
Definition of temperature
The amount of thermal energy that a material possesses
Definition of kinetic theory
Describes the arrangement and movement of particles in solids, liquids and gases
Definition of expansion
When the particles in a substance spread out - ie. The spaces between particles increases
Dissolving and diffusion:
Is calcium carbonate soluble in water
No because the calcium carbonate and water particles are not able to mix
Dissolving and diffusion:
Is copper sulphate soluble in water
Yes because copper sulphate and water particles are able to interact and mix together
What can mass not be
Created or destroyed, it can only be changed from one form into another
Dissolving and diffusion:
What is diffusion
Diffusion is the random movement of particles, when particles diffuse, they spread out and mix with other particles
Dissolving and diffusion:
Give an example of diffusion
the smell of perfume can be detected by people on the other side of a room because the perfume particles diffuse in the air
What is the second definition of diffusion
Diffusion is the random movement of particles from an area of high concentration to an area of low concentration. The particles mix with other particles.
Why do particles in liquids and gases diffuse easily
Because they are free to move around, however, it is possible for solids to diffuse as well
Diffusion of bromine review
When the cover slip that separates the two gases is removed, the brown gas spreads to fill the two containers easily
Why will particles of a gas diffuse faster
The gas particles are moving around faster than the particles in a liquid because they have more energy. This means that the gas particles will spread out more quickly.
Expansion and contraction:
When we increase a materials temperatures what do we do to its particles
When we increase a material’s temperature, we increase the energy of its particles and the material will expand, regardless of whether it is a solid, a liquid or a gas
Expansion and contraction:
Expansion in solids
COLD - particles are sitting at room temperature and vibrating side by side
HOT - when the solid is heated, the particles vibrate more vigorously and nudge each other out of the way. The structure physically becomes bigger
Expansion and contraction:
Why do solids expand on heating
Solids expand on heating because the more heat energy there is in the solid, the faster its particles will vibrate and they push their neighbours further away.
Expansion and contraction:
Give an example of a problem caused when materials (a bridge) which are expanding and contracting occur
Bridges expand in the summer heat and need special joints to stop them bending out of shape
Expansion and contraction:
What happens to the particles in a liquid when they are heated
They move around each other more and take up more room.
Expansion and contraction:
How does a thermometer work
By expansion and contraction of the liquid inside it
It is important to remember that it is the spaces between the particles that change size during expansion and contraction, the particles remain the same size.
WAS JUST A HELPFUL NOTE
What is the definition of a heating curve
Graph to show temperature changes of a substance on heating
What is the definition of a cooling curve
Graph to show temperature changes of a substance on cooling
Definition of temperature
The amount of thermal energy that a material possesses
Definition of kinetic theory
Describes the arrangement and movement of particles in solids, liquids and gases
Definition of expansion
When the particles in a substance spread out - ie. The spaces between particles increases
Experiment: sublimation of a white solid powder:
Method
Place a small spatula of white solid into a boiling tube. Gently heat the solid at the top of a roaring Bunsen flame
Experiment: sublimation of a white solid powder:
Results
The solid doesn’t melt, however there was no solid left at the end. The solid changed directly into a gas. This is known as sublimation
Experiment: sublimation of a white solid powder:
Conclusion
The white solid changes directly from a solid to a gas without going through the liquid phase. This is known as sublimation
What will diffuse faster, the particles of a gas or a liquid
Gas
Increasing the temperature of gas does what to its particles and what does this cause the gas to do
Increases the energy of its particles and it causes the gas to expand
Decreasing the temperature does what to its particles
Decreases the energy of its particles causing it to contract
Changing the volume of a gas:
What does the volume of a gas depend on
It depends on the temperature and pressure of the gas
Changing the volume of a gas:
Increasing the temperature of a gas will do what to its volume
Increase the volume
Changing the volume of a gas:
Increasing the pressure of a gas will do what to its volume
decrease its volume
