thermochemistry Flashcards
theres two kinds of basic energy:
Potential (stored) and kinetic (motion)
Internal energy =
sum of all energy
On molecular scale, chemical bond energy =
potential energy stored in molecular clouds
energies of molecular moition =
Rotationa;, translational, vibrational
thermal energy
sometimes called energy of molecular motion
temperature is a common measure of
energy of molecular motion
ENERGY is the capacity to
do work or supply heat
1st law of thermodynamics
energy cannot be created or destroyed
All total energy of universe is ____
conserved
UNiverse equation
system + surroundings
If energy leaves the system, it must
enter the surroudings
energy change in energy system has to be accompanied by an _______ _______ change and the ____ must be ________
equal magnitude
signs
opposite
ΔE =
Eproducts - E reactants
state function
A function or property whose value depends only on the present state (condition) of the system (path doesn’t matter)
Example of state function
Arriving to Montreal with or with out layovers doesn’t matter. final position is the state function
Most changes to internal energy of system involve ______ of both _____ & ______
transfer
heat
work
ΔESYS =
work (w) - heat (q)
If w (work) = 0 then
it is example of energy transferred only as heat (q)
Heat or thermal energy will flow from _________ to _________ objects, eventually reaching _________ __________
higher-temp
lowe-temp
equal temp
When w = 0, ΔE < 0, q < 0 then
heat released to surrounding
(E initial > E final)
When w = 0, ΔE > 0, q > 0 then
heat absorbed to surrounding
(E intial < E final)
Mechanical work is the product of
w = force (F) x distance (d)
The larger the force or the longer the distance an object is moved, ….
the more work is done ON it
when is transfer of energy work only
when q = 0
