5.1 Units
Just the units.
5.2 relationship between density mass and volume
Density = mass/volume
Mass in Kg or any mass value
Volume in cm3 or any volume unit
Density in kg/cm3 or a/b
5.3 experiment to find density of an object
- Measure mass of the object using a weighing scale and note down the mass
- Use a eureka can that is filled with water to the top and slowly put the object in it
- Measure the volume of the amount of water displaced by the object by collecting the water in a measuring cylinder. This volume will be the volume of the object
- Repeat this with the same object 3 times and find the average for the mass and volume
- Use the formula density = mass/volume to calculate the density
5.4 relationship between pressure force and area
Pressure = force/area
Pressure in Pascals
Force in Newtons
Area in Metres2
5.5 Pressure in fluids
As fluids don’t have a fixed shape, pressure in them acts equally in all direction
5.6 pressure difference
Pressure difference = height x density x g
Pressure difference in Pascals
Height or depth in Meters
Density in Kg/M2
g is the unit for gravity, N/kg
5.7 changed that occur, solid to liquid, liquid to gas
Particles in a solid don’t move, they only vibrate. But as heat is applied the particles gain kinetic energy and start to vibrate faster until they become unorganized and start to slide past each other. At this point they will turn into a liquid, this is melting.
Particles in a liquid are sliding past each other, but as heat energy is applied the particles gain more kinetic energy and they start to bounce off from the exposed area of the liquid and mix in the air. This is evaporation.
5.8 arrangement and motion of particles in solid, liquid and gases
Solid
|
Liquid
|
Gas
|
|
|
|
5.9 Brownian motion for particle theory
Particle theory is about how particles in a gas move randomly in all direction and the pressure exerted by that gas is the total force that particles exert on the surface of that container.
Brownian motion is the phenomena that says particles which are free to move move randomly in all direction. This supports the particle theory as it explained how gas particles hit the inside wall of a container they are in.
5.10 molecules in gas with random movement exert pressure
Molecules in gas move randomly in all directions (brownian motion). For this reason, they hit the walls of container they are in hence exerting pressure.
5.11 why there is an absolute zero temperature
Absolute zero is theoretically the lowest possible temperature at 0K or -273 °C.
At this temperature particles in any element will stop moving completely, they will not hit the walls of the container they are in hence, the pressure will also be 0 Pa at this temperature.
5.12 celsius to kelvin
Just add 273 to a celsius to convert to kelvin.
5.13 increase in temperature results in an increase in average speed of gas particle movement
As temperature increases, particles gain kinetic energy hence they start to move faster.
5.14 temperature of a gas is proportional to the average kinetic energy of its particles
This graph explains how as the temperature of a gas increases the average kinetic energy of its particles also increase.
Here pressure can represent the kinetic energy of particles.
5.15 qualitative relationship between temperature and pressure for gas in container
- As temperature increases, particles gain kinetic energy
- Hence, they move faster
- They exert more force on the inside walls of the sealed container as they hit them with more force and more frequently
- Pressure inside the container increases
5.16 relationship between pressure and kelvin temperature
P1 x T1 = P2 x T2
5.17 relationship between pressure and volume of fixed mass of gas
P1V2 = P1V2
As volume of the gas is decreased, the concentration of the particles increases. Hence the same amount of particles are now hitting smaller surface area hence increasing the force therefore the pressure also.