Energy Flashcards
(31 cards)
Quantitative transfers
Heat of fusion (melting)
Heat of vaporization (boiling)
Eth: specific heat capacity
Ech
Energy stores int he bonds between particles. This is not seen on a heating curve, but only changes during a chemical reaction
Heating
-Occurs when collisions of particles causes an increase in molecular movement. An example of this would be the melting of ice when you put it in warm soda
Radiating
Occurs when energy is transferred from a glowing source giving off photons. Snow melting off your roof in sunlight would be an example.
Q=(delta Hv)(m)
Heat of vaporization times mass
Formula for evaporation/boiling/condensing phase change
When is the heating curve flat and why
WHEN: boiling, melting, evaporating, condensing
WHY: energy add is stored in the phase (Eph) rather than thermally (Eth), so temperature does not change
What is the heat of vaporization
The amount of energy required to boil/evaporate 1 gram of a substance. It can be used to calculate how much energy would be needed to boil a certain amount of a sample.
Formula for boiling
Heat of vaporization times mass
Energy symbol and unit
Q
-Joules or calories
What is heat of fusion
-The amount of energy required to melt 1 gram of a substance and can be used to calculate how much energy would be needed to melt a certain amount of sample.
Energy is energy meaning
- The method of storage doesn’t matter
- Energy can be transferred
- Energy can be stored in different ways
Heating curves
- Up when solid
- Flat melting and freezing
- Up when liquid
- Flat boiling and condensing
- Up as a gas
Melting for freezing formula
Q=(Delta Hf)(m)
Heat of fusion times M
Eth
Energy stored in the speed of the particles. This changes as you increase the temperature of a solid, liquid, or gas. It would change in the slanted sections of a heating curve
What two formulas are for phase changes
The ones with delta H something
Formula for melting
Q=(Delta Hf)(m)
Heat of fusion times M
Formula for freezing
Q=(Delta Hf)(m)
Heat of fusion times M
Energy should be negative bc energy is leaving the system
Q=(Delta Hf)(m)
Heat of fusion times M
Formula for melting or freezing phase change
Formula for condensing
Q= Heat of vaporization times mass
Energy should be negative bc energy is leaving the system
Formula for evaporating
Q= (Heat of vaporization times mass
Transferring energy (2 component systems) rules
Energy in + energy out-> the amount of energy gained by one component in the system should be equal (in a perfect system) to the amount of energy lost by the other component
Tf(final temperature)-> the final temperature of both components should be the same. Amount of energy stored thermally will be identical. Energy transfer until there is equal amount of energy storage, like ice sub in water
Temperature definition
A measure of energy stored in the motion of particles
What is energy
A conserved (same amount beginning and end) substance- like (stuff- like) quantity (measurable) with the capacity (can make things happen) to change
Working
Occurs when one object exerts force on another object. These occur on a level easily seen. So pushing a couch or desk across the floor would be considered work.
