Particle model Flashcards
Solid kinetic theory?
- Vibrations
- Strong forces of attraction keep together
Liquid kinetic theory
- Move random directions, low speed touching eachother with irregular arrangements
- Weaker forces of attraction
Gas kinetic theory
- Almost no forces of attraction
- Free to move high speed in random directions
What is the solid to gas change of state?
- Sublimation
How to find density of a solid? CP
- Use a balance to measure objects mass
- Fill eureka can to the spout
- Submerge object in eureka can
- measure water pushed out in ml
- 1ml is 1cm^3
how to find density of a liquid? CP
- Add a measuring cylinder to a weighing scale and zero the balance
- Add 10ml of liquid.
- Measure and record the density
- Repeat previous two steps until measuring cylinder is full
- Find average of density
What is conserved in state changes?
- Mass is conserved
What happens when you heat a system?
- More energy in particles
- Particles vibrate/move around more
- The temperature of the system increases, OR changes state
What is specific heat capacity? and what is its equation?
- Energy required to raise the temperature of 1kg of a substance by 1 degree[
- Change in thermal energy = m x specific heat capacity x change in temperature
What is specific latent heat? what is its equation?
- Energy needed to change the state of 1kg of a substance without a change in temperature
- Specific latent heat for melting/freezing and boiling/condensing are different
- Thermal energy for state change = m x L(specific latent heat)
How do you obtain a time temperature graph for the changing of states in water
- Take crushed ice and fill a beaker with it
- Keep a thermometer in it
- Keep the beaker on a tripod and gauze above the bunsen burner
- Heat it gradually
- Measure the temperature every 20 seconds and note the times when the ice seems to melt
- Draw a graph after this
- Flat parts are change of state
Why does temperature not change during change of state?
- Energy used to break bonds instead of being used in kinetic energy
How do you find the specific heat capacity of water?
Take a styrofoam cup, place it onto a mass, zero it out and fill the container with water.
- Add a joulemeter and put an electric immersion heater into the water. Connect the immersion heater to the joulemeter
- Add a thermometer
- Measure the temperature of the water and turn on the power.
- Wait till the temperature has risen by 10 degrees
- Record the energy on the joulemeter and calculate the change in temperature
- Use change in temperature = m x c x change in temp to find the specific heat capacity
- repeat the experiment
How to improve heat related experiments?
- Use insulation
- such as wrapping the container in cotton wool
- Keep the container on an insulating surface like a cork mat
- Reduces rate of energy transfer by heating, less energy transferred to surrounding
How does pressure in a gas work?
- Gas particles move at high speeds
- Bang into each other and container walls
- Exert a force
- in a container, gas pressure is the total force exerted by all particles in the gas on a unit area of container walls at right angles
- Higher temperature, more collisions, more force higher pressure
