Particle model of matter Flashcards
What conclusion can be made between pressure and volume when mass and temperature is constant?
They are inversely proportional. Shown by P1V1 = P2V2 as they make a constant.
Explain why the pressure in gas increases as the gas is compressed at a constant mass and temperature (in terms of volume)
As gas is compressed the volume decreases. Particles are closer together so the frequency of successful collisions against the container surface at right angles increase. Each collision causes a force so the net force increases and pressure is the total force per unit area.
Explain why pumping a bike pump increases temperature of the tyres.
Compression (a force) means work is done on the tyres. Therefore, (kinetic) energy is transferred and increases the internal energy of particles. This means the average kinetic energy of gas particles increases so temperature increases.
Explain why increasing temperature at a fixed mass and volume increases pressure.
Gas particles gain more kinetic energy and move faster. Therefore, increased frequency of successful collisions. Greater net force on the same fixed area and pressure is force over area.
Explain how energy being transferred to the surroundings affects SLH.
The students value would be higher as less energy would be transferred to the water for it to change state
How do heating graphs show SHC?
Gradient
Describe the process of conduction.
Atoms gain kinetic energy and collide with neighbouring atoms, spreading through structure
Explain how evaporation of a liquid causes cooling.
Particles have enough energy to evaporate and escape from the surface of water. Lower mean kinetic energy of remaining particles. The lower mean energy means the lower temperature.
Explain a heating graph.
Temperature initially increases at a constant rate until melting point is reached where temperature is constant as energy is transferred to break bonds for melting. Temperature increases again once all bonds have been broken until reaches boiling point.
Why are solids difficult to compress?
Particles are tightly packed close regular arrangement together so there is no room for them to move any closer.
Explain why internal energy of air increases as tyre is inflated
Work is done as a force is exerted (by compression) which transfers energy so average kinetic energy and temperature of particles increases
Some water evaporated before reached 100 degrees, how does this affect SLH?
Lower value as smaller mass changed state at b.p
If the temperature of the system increases what does the increase in temperature depend on?
- SHC/type of material
- mass
- energy input
Explain the changes in arrangement and movement of particles as ice melts and temperature increases.
- Solid ice has particles arranged in a fixed regular arrangement with particles only vibrating around a fixed point due to strong forces
- As ice is melted energy is transferred to particles so they vibrate faster and gain kinetic and potential energy so internal energy increases until the particles have enough energy to change state into a liquid
- Whilst changing state temperature remains constant until completely changed state as internal energy increases to break bonds not raise temperature
- Liquid has a close but irregular random arrangement and can flow freely as these particles have more energy and weaker forces
Explain why pressure increases as more air is pumped into the tyre.
More air means more particles so more frequent successful collisions. Work is also done by the force of compression so more energy is transferred to these particles.
