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Talk about the quick summary of the state of matter is so solid, liquid and gas
Solid is small and has strong lattice with strong forces of attraction and vibrate
Liquid, there are some gaps, less ordered, slow motion, flows easily
Gas out large gaps and no order therefore no forces of attraction and they are fast and move randomly
What is Internal energy mean and what is the equation for?
Why do molecules have Ek and Ep?
The sum of random distribution of kinetic and potential energies of the molecules in a system
U=sum of Ek + sum of Ep
Molecules have EK because of their motion and they have EP due to their position (Into molecular forces)
What is thermal energy transfer? What are the three types?
Thermo energy transfer only occur if there is a temperature difference between the system and its surroundings. The three types are conduction, convection and radiation.
Explain the three types of thermal energy transfer
Conduction is where the energy transfer by lattice vibration and heat transfer in non-metallic crystals therefore free electrons move randomly in the lattice. This occurs in a solid and requires particles.
Convection is in a liquid and gas or any fluids and rise due to the temperature increase and falling due to colder more dense fluids. For example, hot molecules mean an increase in EK or molecules entering a colder fluid means an increase in average EK which equals a temperature rise
Radiation is the quantity and wavelength of radiation depending on the temperature
What is thermal equilibrium?
No net thermal transfer when system and this surroundings are the same temperature therefore two different temperatures will create an average EK for all molecules
What is considered an ideal gas?
No intermolecular forces therefore no EP
What is the first law of thermodynamics?
What is the equation and state an easier way to remember this?
An increase in internal energy is equal to the sum of energy transferred TO the system by heating/energy by work done ON it by external forces.
A decrease in internal energy is equal to the sum of energy transferred away from the system BY cooling/energy transferred AWAY from the system DOING work done AGAINST external forces
Change in U=+- change in WD +- change in Q (heat energy)
On=+wd (compressed)
By=-wd (expands or escapes)
Added to=+q (enters)
Given off=-q (leaves)
State the terms isothermal, isometric, isobaric, adiabaric
Takes place at the same temperature
Same value
Same pressure
Takes place so fast the change in Q = zero
How do you change Kelvin to degrees vice versa?
Kelvin=degrees+273
Degrees=kelvin-273
What are the equations can be used for Q?
Since Q is heat energy, this means any energy equations can be used
Ep=mgh
Ek=1/2mv²
Q=It=ne=eV
Q=Pt
How do you calculate the internal energy from the equation force equals pressure x area?
Force=wd
Change in Wd=pressure x area x difference in width
Change In Wd= pressure x volume
So the internal energy (U)=+-pV+-change in Q
What does specific heat capacity mean? And what is its equation and units?
Energy needed to raise the temperature of Unit mass 1 kg of material by one Kelvin
C=Q/(m x change in temp) or Q=m x c x change in temp
SHC. Measured in Jkg^-1K^-1
How do you calculate power using the specific heat capacity equation?
Q=m x c x change in temp
Q=Pt
P=(m x c x change in temp) over time
What is specific latent heat and what is its equation and units?
Thermal energy required to change the state of 1 kg without a change in temperature
L=Q/m
Jkg^-1
State and explain the two different ways to achieve specific latent heat (changing states)
Heat of fusion is the change from solid to liquid through melting or freezing
Heat of vaporisation is the change from a liquid to vapour through condensation or vaporisation
Explain Boyles law and its equation
For fixed mass of gas at a constant temperature, the volume is inversely proportional to the pressure
P1V1=P2V2
Explain the pressure temperature law/ amonton’s law and its equation
For fixed mass and volume of gas, the pressure is directly proportional to the absolute temperature of the gas
P1/T1=P2/T2
What is the definition for absolute zero?
The coolest temperature possible when the pressure is zero the molecule stop moving therefore 0EK
Explain Charles law and that equation
For fixed mass of gas at a constant pressure the volume is directly proportional to the absolute temperature
V1/T1=V2/T2
You can combine all the laws together what is the equation?
P1V1/T1= P2V2/T2
What is a mole?
Number of atoms in 12 g of carbon 12
What is the two equation to find the number of moles?
n=N/Na (molecule/avogadro constant)
n=m/M (mass of gas’s/molar mass)
Molar mass is the no. At the bottom of an element
What are the two equations for pV?
pV=NkT
pV=nRt
What were Brownian’s motion observations?
Smoke particles move randomly and continuously
Air molecules move randomly and continuously
Ammo must be smaller than the smoke particles and there must be a large number of molecules
What are the molecular theory assumptions?
Large number of molecules move randomly
Volume of gas molecules is negligible compared to volume occupied by gas
No intermolecular forces until collision
Collision between wall and molecules are elastic
Time of collision is negligible compared to the time between collisions
Between collision motion is in a straight line and a constant speed
What is the kinetic theory equation for one molecule and how do you use the kinetic theory equation using density?
pV=1/3 Nm (Crms)²
P=1/3 N x row x (Crms)²
How do you calculate the root means squared speed?
Square root ((s1)² +(s2)² so on) all over the no. Of speeds
How do you calculate the average EK?
Ek=1/2 m (Crms)²
Ek for 1 molecule= 3/2 kT
Ek for 1 mole= Ek for 1 molecule x Na
Ek for no. Of moles = 3/2 kT x (no of molecules) so n x Na
Ek= (3RT/2Na)
What does it mean when it ask for the internal energy?
Don’t forget the internal engine is just the sum of EK and EP so you use your equation for average EK to get the answer
How do you calculate the factor of Crms
Crms is directly proportional to square root of temp
Square root temp 1 over square root temp 2