States of matter Flashcards
Revision notes
What are the properties of liquids gases and solids?
What are the properties of liquids gases and solids?
Solids:
-Keeps its shape.
-Particles are tightly packed and don’t move much.
-Can’t be squished easily.
-Doesn’t flow.
Liquids:
-Takes the shape of its container.
-Particles are close but can move around each other.
-Can be squished a little.
-Flows like water.
Gases:
-Fills the entire container it’s in.
-Particles are spread apart and move freely.
-Can be squished a lot.
-Flows like air.
What are the structures of solids, liquids and gases in terms of particle separation, arrangement and motion
Solids:
-Keeps its shape and volume.
-Particles are tightly packed and don’t move much.
-Hard to compact.
-Doesn’t flow.
Liquids:
-Takes the shape of its container but keeps its volume.
Particles are close but can move around each other.
–Can be compacted a little.
-Flows like water.
Gases:
-Fills the entire container it’s in and expands to fit.
-Particles are spread apart and move freely.
-Can be compacted a lot.
-Flows like air.
What are the changes of states in terms of melting, boiling, evaporating, freezing and condensing?
Melting: This is when a solid turns into a liquid. Think of an ice cube melting into water. The solid’s particles gain enough energy to break free from their fixed positions and start moving around, turning into a liquid.
Boiling: Boiling happens when a liquid turns into a gas. If you heat water in a kettle, you’ll see it start bubbling. This is because the water is gaining so much heat energy that its particles move fast enough to escape into the air as vapor.
Evaporating: Evaporation is similar to boiling but occurs at the surface of a liquid at any temperature. When you leave a puddle of water in the sun, it disappears over time. This is because some of the water particles near the surface gain enough energy to escape into the air as vapor.
Freezing: Freezing is the opposite of melting. It’s when a liquid turns into a solid. For instance, when you put water in the freezer, it eventually turns into ice. As the temperature decreases, the particles slow down and come together to form a solid structure.
Condensing: Condensation is the opposite of evaporating. It occurs when a gas turns into a liquid. You can see this when steam from a hot shower hits a cold mirror and forms droplets of water. The gas particles lose energy and come together to form liquid droplets.
What are the effects of temperature and pressure on the volume of a gas?
Temperature:
When you increase the temperature of a gas, its particles gain more energy and move faster.
Faster-moving particles bump into each other and the container walls more frequently.
This increases the pressure and causes the gas to expand, increasing its volume.
So, higher temperature generally leads to a larger volume for a gas.
Pressure:
When you increase the pressure on a gas, you squeeze its particles closer together.
This reduces the space between particles and decreases the volume of the gas.
Conversely, reducing the pressure allows the gas particles to spread out more, increasing the volume.
So, higher pressure generally leads to a smaller volume for a gas, and lower pressure leads to a larger volume.
Can you explain the changes of state in terms of kinetic
particle theory, including the interpretation of
heating and cooling curves?
Solid to Liquid (Melting):
In a solid, particles are tightly packed and vibrate in fixed positions due to their low energy.
When heat is applied, the particles gain energy and vibrate faster.
Eventually, the particles have enough energy to overcome the forces holding them in place, causing them to break free and slide past each other, forming a liquid.
This process is called melting.
Liquid to Gas (Boiling/Evaporating):
In a liquid, particles are still close together but can move past each other.
Heating increases the energy of the particles, causing them to move faster and spread out.
Some particles at the surface gain enough energy to escape into the air as vapor in a process called evaporation.
When the entire liquid reaches its boiling point, the pressure of the vapor equals the pressure exerted on the liquid, and bubbles form throughout the liquid. This is boiling.
Solid to Gas (Sublimation):
Some solids can turn directly into gases without becoming liquids first. This process is called sublimation.
In sublimation, solid particles gain enough energy to break free from their fixed positions and spread out as a gas without passing through the liquid phase.
Interpretation of Heating and Cooling Curves:
A heating curve shows how the temperature of a substance changes as heat is added over time.
As heat is added, the temperature increases steadily until it reaches the melting or boiling point, where it plateaus as the energy is used to break intermolecular bonds.
Similarly, during cooling, the temperature decreases until it reaches the freezing or condensation point, where it plateaus as the energy is released during bond formation.
The flat parts of the curve represent phase changes where the energy is used for breaking or forming bonds rather than increasing or decreasing the temperature.
The slope of the curve indicates how fast the substance is gaining or losing heat. A steeper slope means faster heating or cooling.
Can you explain in terms of kinetic particle theory, the effects of temperature and pressure on the volume of a gas?
Temperature:
According to kinetic particle theory, gases consist of particles in constant, random motion.
When you increase the temperature of a gas, you’re adding energy to these particles.
This added energy causes the gas particles to move faster and collide with each other and the walls of their container more frequently and with greater force.
As a result, the gas particles exert more pressure on the walls of the container.
The increased energy and pressure lead to the gas occupying more space, thus increasing its volume.
So, higher temperature means faster-moving particles, more frequent collisions, higher pressure, and larger volume for a gas.
Pressure:
If you increase the pressure on a gas, you’re essentially squeezing the gas particles closer together.
With less space between particles, they collide with each other and the walls of their container more often and with greater force.
This increases the pressure exerted by the gas.
Conversely, if you decrease the pressure, the gas particles have more space to move around, leading to fewer collisions and less force exerted on the container walls.
This results in a decrease in pressure and an increase in volume.
So, higher pressure means closer-packed particles, more frequent and forceful collisions, higher pressure, and smaller volume for a gas.
Can you describe and explain diffusion in terms of kinetic particle theory?
Diffusion is when particles spread out evenly from an area of high concentration to an area of low concentration.
According to the kinetic particle theory, all particles are constantly moving.
When there’s a high concentration of particles in one area, they bump into each other and move around randomly.
Some of these particles move away from the crowded area and into less crowded areas.
Over time, this random movement causes particles to spread out evenly.
This happens because particles naturally move from where there are many of them to where there are fewer, until they’re evenly spread throughout the space.
So, diffusion is the natural process where particles spread out from crowded areas to less crowded ones because they’re always moving around.
Can you describe and explain the effect of relative
molecular mass on the rate of diffusion of gases
Lighter gas molecules diffuse faster than heavier ones.
Lighter molecules have lower relative molecular masses and move faster due to having less mass to slow them down.
For example, hydrogen (H2) molecules, being light, diffuse more rapidly than oxygen (O2) molecules, which are heavier.
In essence, the lighter the gas molecules, the faster they diffuse compared to heavier ones.
