Thermodynamics Flashcards
when delta H is > 0 what does it mean
the reaction is endothermic the system absorbs heat
what is enthalpy and it signs
the change in heat in a system during a chemical reaction at constant pressure (heat lost or gained and delta H
what are the 3 laws of thermodynamics?
- energy is conserved( can never be lost)
- entropy of an isolated system increases (max energy dispersal) “ the universe tend towards max entropy”
- temperature cannot go below 0 kelvin
when delta H is < 0 what does it mean
the reaction is exothermic , the system loses heat
what is entropy ?
the way energy is dispersed
what does spontaneous mean and example
a process the occurs without continous input of energy ,when an endothermic (delta H> 0) reaction can be energy favourable and the entropy changes both the surroundings and system together is positive ex an ice cube at room temp it will spontaneously melt and S universe must be > 0, delta G < 0
what is detla G
it is gibbs free energy
when is delta G knot used for
when at constant temp and pressure at the standard state
at equlibrium what is delta G and Q
delta G = 0 , Q=K eq
when is delta G knot = -RTknKeq used and when is delta G= dela G knot + RTln [C]^c [D]^d/ [A]^a [B]^B used
- at equlibrium
- not at equlibrium
when delta G knot is less than 0 what does it mean
it is favourable
what is the temperature when looking for G using concentration
its 298 K bc it as room temp
(273+25)
what happens if K> Q ?
it shift for products
what happens if Q> k?
it shifts for reactants
what is a coupled reaction and what is an example
coupling an unfavourable reaction to a favourable reaction to push the direction of the reaction ex glucose coupling with atp to push for glucose 6P
what are the 3 high energy phosphate over ATP?
1.Phosphoenol pyruvate (PEP)
2. Creatine phosphate (CP)
3. Acetyl Phosphate
Even though the other are higher in energy why is ATP the energy currency of the cella
can revert back and forth easily between ADP to ATP whilst PEP cannot revert back
