Module 3 Flashcards
How is energy transferred?
From regions of high temperature to regions of low temperature.
Thermal equilibrium
When two objects are in contact with each other and are the same temperature, there is no net transfer of energy between them.
Celsius to kelvin?
Add 273K
What is the celcuis scale based on?
Freezing and boiling point of water
What are the problems with the celcuis scale?
The boiling and freezing point changes according to pressure
What is the arrangement of solids?
Particles vibrate in a fixed position
If temperature increases the amplitude of vibration increases.
Spacing between atoms are very small
What is the arrangements of liquids?
The particles can flow past each other. They vibrate but not in a fixed position.
What is the arrangement of gases?
Particles are far apart. They don’t exert forces on each other expect during collisions. Particle move in random morion
How can brownian motion be demonstrated?
Using smoke cells or pollen grains in a liquid.
Observation seen in brownian motion?
The smoke particles move in random motion. The air particles cannnot be seen
What are the conclusions from brownian motion?
The smoke particles are colliding with the air particles, which must also be moving in random motion. The air particles must be smaller then the smoke cells.
Internal energy
The sum of the randomly distributed kinetic energy and potential energy of all particles of a substance
When a substance is changing state, what energy increases?
KE is constant. PE is increasing by breaking the bonds.
Temperature is constant.
Specific heat capacity
The energy to raise the temperature of 1 kg of a substance by 1 K
What is specific latent heat?
The energy per kg required to change its state without changing its temperature.
Specific latent of fusion
The energy per kg required to melt a substance at a constant temperature
Specific heat of vaporisation
The energy per kg required to vaporise a substance at a constant temperature
Heat
Type of energy (J)
Temperature
Measure of hotness of an object (K)
.
.
B
D
What is the molar mass?
Tells us how much the mass of one mole of a substance weighs.
Eg. Water = 18g/mole
How do you find the number of atoms or molecules?
Moles X avogadro
Why do we use root mean squared speed?
Many different particles have different speeds. So you can find the average velocity using this.
Assumptions:
R-Random motion. large number of particles have rapid,random motion
A- Attraction. Negligible forces of attraction between particles except during collisions.
V-Volume. Individual particles occupy negligible volume compared to the volume of gas.
E-Elastic collisions.
D-Duration of collisions. Time spent in collisions is negligible compared to time spent between collisions.
What are the forces of ideal gases?
Zero forces except during collisions.
The potential energy is assumed to be 0.
PV=nRT
n= number of moles
R= gas law constant