Unit 6- Thermochemistry Flashcards
Thermodynamics
the study of energy and its transformations
Thermochemistry
study of the relation between chemical reactions and changes in energy
Thermochemical equilibrium
a condition in which termperature is uniform throughout a material and no energy flows from one point to another
Energy definition
The capacity to do work
Law of conservation of energy
Energy can neither be created nor destroyed, but it can be converted from one form to another
ex. Potential to kinetic energy, and chemical energy to thermal energy
First law of thermodynamics
Law of conservation of energy… so eergy gained or lost by a system must equal the energy lost or gained by surroundings
System
the part of the universe that is the focus of a thermochemical study (isolated/open/closed)
Surroundings
everything in the universe that is not part of the system
Open system
can exchange matter and energy with surroundings
Closed system
can exchange energy but not matter with surroundings
isolated system
does not exchange matter or energy with surroundings
Endothermic state changes
melting, evaporating, sublimating (solid to gas)
exothermic state changes
freezing (fusion), condensing, depostition (gas to solid)
loss of kinetic energy caused by release of heat by molecules
Exothermic process
energy flows out of system to surroundings
endothermic process
energy flows into system from surroundings
