Fuel metabolism Flashcards
What is enthalpy
H, total energy present in the system
H=q=U+PdeltaV
if theres more energy after enthalpy increases, if its less energy, enthalpy decreases
is endothermic reaction enthalpically favored or unfavored?
unfavorable delta H>0
heat must be gathered from the surroundings and condenses into the system
is an exothermic reaction enthalpically favorable
yes, favorable delta H < 0, heat can dissipate from the system and spread out more within the surroundings
what is the second law
entropy, S, of the universe (system + surroundings) increases in all chemical and physical processes
equation of gibbs free energy and what each means
deltaG =deltaH-TdeltaS
G- total change in free energy of a reaction system
H- total change in enthalpy of a reaction system
S- total change in entropy of a reaction system
T - absolute temperature (K)
think of car analogy if deltaG is negative for the forward reaction is the reaction exergonic or endergonic
exergonic, releasing free energy
think of car analogy, deltaG of 0 signifies ?
a balance between the forward and reverse reactions
think of car analogy if deltaG is positive, would the reverse reaction occur spontaneously? is its endergonic or exergonic
spont, endergonic
the maximal energy available that can be absorbed in an endothermic reaction is limited by what
T delta S
what is enthalpy (H)
measure of potential energy of a system found in intermolecular attractions and chemical bonds
explain phase changes of enthalpy
solid - liquid - gas (endothermic)
gas-liquid-solid (exothermic)
endothermic
gases have more heat energy than liquids and liquids have more heat energy than solids
exothermic
reactions release heat
what is entropy (S)
chaos. energy spread throughout a system or between system & its surroundings
entropy is maximized at equilibrium
formula to calculate deltaG from deltaG
deltaG =deltaG’o +RT * 1n (Q)
deltaG; the actual free energy change you want to find
delta G’o: the starting point value under standard conditions
R: A constant (like a fixed number) thats always the same
T temperature in kelvin
1n(Q) the natural logarithm of something called the reactions quotient , measure of how far the reaction has progressed from standard conditions
