Enthalpy/Entropy Flashcards
describe an exothermic reaction in relation to the products and reactants
products have less energy than reactants
deltaH<0
entropy does what to energy
entropy is a dispersion of energy, and state function.
-atomic freedom
when can you get a non-spontaneous reaction with gibbs?
deltaG>0, delta S universe<0= non-spontaneous
0 thermodynamics law
if 2 things are same temp, 3rd also same temp
formula for endergonic
delta G>0
gibbs free energy equation
G=-TS
delta G=delta H-TdeltaS
1 thermo law
energy is conserved
E of the universe -0
is enthalpy a state function
yes
gibbs free energy formula
G=H-TS
g=gibbs
H-enTHalpy
T-temp
S-enTROpy
gibbs free energy
state function (G) -reaction is exothermic
2nd law thermodynamics
ALL process, entropy of uuniverse, increaess. Energy of universe tends to spread. ENERGY SPREADS OUT
how can chem rxn work
PV and electrical work. PV is most common
w>0
works is done on the system, “physically” put work into it
negative enthalpy is exothermic or endothermic
exothermic
every substance has a different specific heat capactity which is caused by/because
the amount of heat required to raise 1 gram of it to 1C
why is there a change in enthalpy?
(mostly) requires breaking down chem bonds in reactants, energy produced is forming chemical bonds in products
3rd thermo law
perfect crystal @ abs zero has entropy
describe the relations of entropy
high disorder: deltaS >0
low disorder: deltaS<0
what is g the measure of in gibbs free energy
measure of energy
isothermal
constant temp
what happens to enthalpy when energy is reduced
height and constant increases (deltaH>0)
how can order be desribed in natural processess
order to disorder
when does an endothermic reaction occur
when T delta S is large
1st law of thermo
matter cant be createor destroyed just converted or transfered
what does the 2nd law of thermodynamics predict
whether chem reaction is spontaneous or notq
Entropy
measure of disorder in system
non-spontaneous reactants
enedergonic
state function
depends ONLY on CURRENT state of system
state function
property that depends only on the condition (state) of system, not path taken to system
what type of reactions are NOT spontaneous
ENDOthermic
gibbs free energy
simplifies carious calulatiosn and comparisons
give examples of state functions
energy volume temp number of moles pressure
formula to calculate entropy
define each varaible
(sum)nS,products-(sum)mS,reactants= deltaSrxn
practically the sum of the enthalpy of the products minus the sum of the enthalpy of the reactants
rxn- reaction
n and m are stoichiometric coefficients
entHalpy equation
H=U+PV
deltaE>0
system gains energy
when van you get a spontaneous reaction with gibbs
deltaG<0, delta S universe>0= spontaneous reaction
describe spontaneous reaction characteristics
highly exothermic
-exothermic and endothermic can be spontaneous
internal energy equation
q=deltaU-W
U-internal energy
W- negative, system does work on surroundings
P- pressure
whats the heat equation
q=mc(delta)T "q=MCAT" q- heat gained by system c-specfic heat of substance m-mass delta T-change in temp.
what happens to enthlalpy when energy is produced
height and energy decrease (deltaH<0)
what type of reactions are spontaneous
Exothermic
enthalpy equation
H=E+PV
h-enthalpy
E-energy
P-pressure
V-volume
q>0
system gained heat, surroundings loose heat
whats the formular for a system thats subject to change
deltaT= t2-t1
this form can also be used for volume
work equation
w+fxd
f-force
d-distancec
why is gibbs free energy a state function
all other variables in equation are state functions
isobaric
constant pressure
spontaneous reactants
exogonic
mnemonic to remember gibbs free energy formula
god fish are horrible without tatar sauce
energy
ability to do work
what is enthalpy in an endothermic reaction
deltaH>0
if the number of moles of a gas increases, what happens to the entropy
in # of moles of gas increases during a rxn, the change in entropy is less than zero
(deltaS<0)
why is the total energy of the universe contant
1st law of thermo
formula for exergonic
deltaG<0
