End Of Unit Flashcards
What are the changes of state ?
Gas -> solid =
Solid -> gas =
Liquid -> solid = freezing
Solid -> liquid = melting
Liquid -> gas = evaporation
Gas -> liquid = condensation
State 2 properties of solids
Strong bonds Can’t compress Vibrate Keep shape High density
State two properties of a gas
Fast moving particles Particles far apart Can compress Expand to fill the container Low density
State two properties of liquids
Can’t compress
Strong bonds but allow flow
Take shape of the bottom of the container
Less dense than a solid but more dense that a Gas
What is density
The relationship between mass and volume
How do you calculate density
Mass/volume P=m/v
Calculate the density of 7074kg of iron girder with a volume of 0.9 cubed
7074/0.9 = 7860kg/m cubed
What is the name of the can used to investigate the density of objects
Displacement or eureka can
What is specific heat capacity
The amount of heat needed to raise the temperature of 1kg of substance by 1 degree
What is specific latent heat
The amount of energy it takes for 1kg of substance to change state
State the unit for pressure
Pascals
What is the temperature of absolute zero
-273 degrees
0 kelvin
How do you convert between Celsius and kelvin
C -> k = +273
K. -> c = -273
Absolute zero = -273ºc / 0k
Freezing point of water = 0º/273k
Boiling point of water = 100º/373k
What is the relationship between kinetic energy of particles and kelvin temperature of gas
Linear proportional
What is the equation for pressure ?
Force = pressure / area
P= pressure = pascals A= area = metres squared F= force = 1 newton/ metre squared
Define pressure ?
Amount of force acting on an area
How do you reduce pressure ?
Spread the weight out
Increase the area
Reduce temperature
What direction does pressure act in ?
All directions towards the object and at right angles to the objects surface
What is the specific latent heat equation ?
Energy transferred = mass X specific latent heat
Q= energy transferred = joules M= mass = kilograms L= latent heat = J/Kg
What is the specific heat capacity equation ?
E= m X c X Ø
E= energy transferred = Joules M= mass = kg C= specific heat capacity = J/kg degrees C Ø= Temperature change = degrees
What is the specific heat capacity core practical ?
Use scales to measure mass of insulating container
Fill with water and measure again the difference between these measurements is the mass of water in container
Put the water in a insulating container and attach a thermometer and electric immersion heater attached to a Joulmeter with power making sure the joulmeter reads zero
Measure water temp and turn on power
When temp increased by 10º record joulmeter and increase in temp
Then use equations with measurements found
Define density ?
A measure of compactness of a substance
The mass of a substance to how much space it takes up
What is the density core practical ?
2) Measure the mass (m) of the object using mass balance Fill the bottle with a liquid of a known density (e.g. water) g) Place the stopper into the bottle and dry the outside 4) Measure the m ass of the bottle (m2). Empt the bottle and place the object into the density bottle Repeat steps 2 and 3. Measure the mass of the bottle (m3)Calculate the volume of displaced water: The mass of the displaced water = m2 - (m3 - m1) You know the density of water, so you can use V = m/p This equals the volume of the object Calculate the density of the object using p = m /V with the mass you measured in step l (m) and the volume you calculated in step 6
In volume what does 1ml equal ?
1cm cubed
What happened when you heat a liquid ?
The extra energy is transferred into the particles kinetic energy store making them move faster and then when the particles have enough energy they overcome there attraction to each other forming has bubbles in the liquid which is evaporation
What changes as particles change stage ?
Density
Solid = most dense Gases = least dense
Regarding specific latent heat what is melting and freezing
And what is evaporating , condensing and boiling
Specific latent heat of fusion = melting / freezing.
Specific latent heat of vaporisation = condensing , boiling , evaporating
What happened when gas particles collide ?
When gas particles collide they exert a force on the container and as the force increases so does the temperature
What is the density of water ?
1 g/cm cubed
1kg/m cubed
Kinetic energy in solids ?
They don’t have much energy in their kinetic energy stores so they can only vibrate about in their fixed positions
Kinetic energy stores in liquids ?
They have more energy than a solid in their kinetic energy stores, they can move over each other in random directions at low speeds
Kinetic energy stores in gases ?
They have lots of energy in their kinetic energy stores and are able to live around in random directions at high speeds
What factors are effect the amount of stored up thermal energy ?
Temperatures
Mass
Material the substance is made form
What happens when a substance changes state regarding mass, volume and density ?
As you move from solid to gas it becomes less dense
Mass stays the same
Volume changes as the particles spread apart
What happens a when has particles collide ?
They exert a force, in a sealed container, the outward gas pressure is the told force by all of the particles in the gas on a unit area of the container walls
How does temperature affect gas pressure ?
The high temp means particles move quicker and collide more making more force exerted and thus more pressure
What is the relationship between kelvin and kinetic energy of particles?
At absolute zero (0K) but (-273ºc) the particles have as little as energy in their kinetic energy stores as possible, their pretty much still
What is the specific latent heat of fusion ?
Changing between a solid and a liquid (melting and freezing )
What is the specific latent heat of vaporisation ?
Changing between a liquid and a gas
Evaporating / boiling/ condensing
What happens if surface area of a fluid increases
Pressure decreases
What happens to fluid pressure with depth ?
It increases
