APCHEM THERMODYNAMICS Flashcards
(25 cards)
Kinetic energy
The energy of motion (ex-thermal, chemical, sound energy)
Energy
The study of heat and work
Potential energy
The energy of position or stored energy (ex- chemical or gravitational energy)
Thermal energy
Motion of subatomic particles, all matter has this
Mechanical energy
Motion of a large group of particles, moving parts
Sound energy
Corresponds to compression and expansion of the spaces between molecules
Chemical energy
Resulting from the attraction of electrons of nuclei in molecules
Gravitational energy
When any matter is held above ground
First law of thermodynamics
Energy cannot be created or destroyed, only transferred
Heat
When 2 objects of different temperatures meet
Principles of heat
Heat transfers from hot to cold
The transfer continues until thermal equilibrium is reached
Heat lost = Heat gained
Exothermic
Heat is transferred from system to surroundings
Endothermic
Heat is transferred from surroundings to system
1 calorie =?
4.184 J
On a graph, the flat lines symbolize what?
Phase changes
Which phase changes are endothermic?
Evaporation, sublimation, melting
What are the exothermic phase changes?
Freezing, condensation, deposition
With the flat lines on the graph (phase changes) what happens to the energy?
Breaks up IMF’s
With the slanted lines on the graph, what happens to the energy?
The energy increases the speed of the particles
Hess’s Law
If a reaction is the sum of two or more reactions, the change In Enthalpy is the sum of the delta H values of those reactions
Enthalpy
The heat content of a substance at constant pressure
State Function
A quantity that is only dependent on the initial and final states of the reaction, not on the path by which it got there
Specific heat capacity
Quantity of heat required to raise 1 gram of a substance by 1 kelvin
Calorimetry
A laboratory technique that determines the amount of heat transferred in a chemical or physical process
