Energy Changes and Rate of Reaction Flashcards
What is thermochemistry?
Energy changes involved in physical and chemical processes
What is kinetic energy?
Associated with the motion of an object
What is potential energy?
Stored energy due to an objects position
What are joules?
the SI units of energy kg m^2/s^2
What is a system?
A sample under observation
Define the surroundings
Everything in the universe that is not the system
What is an Open system?
Both matter and energy can flow freely
What is a closed system?
Energy can flow freely but not matter
What is an isolated system?
Neither matter nor energy can flow freely (ideal but impossible)
What is thermal energy?
It is the total of the kinetic energy of the molecules (energy in motion) and the potential energy (energy of the bonds holding the molecules together)
What is temperature?
It is a measure of the average kinetic energy of the molecule in a substance
What is specific heat capacity?
The amount of heat energy required to raise the temperature of 1g of a substance by 1 C or 1 K. c = j/g C. Depends on state, temperature and pressure of a substance
What is the first law of thermodynamics?
The law of conservation of energy.
Energy can be transformed from one form to another but it cannot be created nor destroyed
What is Enthalpy, H?
The heat content of a system or total energy of the system plus pressure times volume, H = E + PV
Define endothermic
Positive enthalpy change when heat enters a system
