Thermochemistry Flashcards
(24 cards)
capacity to do work
energy
chemistry defined - as directed energy change resulting in process
work
energy that comes from the sun and is earth’s primary energy source
radiant energy or solar energy
energy associated with the random motion of atoms and molecules
thermal energy
energy stored within structural units of chemical substances
chemical energy
energy available by virtue of an objects position
potential energy
the transfer of thermal energy between 2 bodies that are at different temperatures
heat
the study of heat change in chemical reactions
thermochemistry
the specific part of the universe that is of interest to us
system
the rest of the universe outside a system
surrounding
can exchange mass and energy, usully in the form of heat with its surroundings
open system
allows the transfer of energy (heat) but not mass
closed system
does not allow the transfer of either mass of energy
isolated system
properties that are determined by the state of the system, regardless of how that condition was achieved; only the start and end points matter rather than the path taken
state functions
the first law of thermodynamics
energy can be converted from one form to another but cannot be created or destroyed
energy that is transferred from one body to another as the result of a difference in temperature
heat (q)
energy transferred to or from an object via the application of force along a displacement
work (w)
the unit for work done by or on a gas is -
liter atmospheres
1 L atm = ?
101.3 J
when a process occurs at a constant pressure, the heat evolved (released or absorbed) is equal to the -
change in enthalpy
it is the sum of internal energy and the product of pressure and volume
enthalpy
who developed hess law
germain hess
it is based on the idea that energy is conserved and cannot be created or destroyed
hess law
hess law states that
the enthalpy change of a chemical reaction is independent of the path taken
