Chemistry Test 4 Flashcards
enthalpy
heat in joules, H
Gibbs Free Energy
work in joules, G
entropy
disorder in joules, S
characteristics of entropy
- gas is greater entropy than that of liquids and solids
- entropy of a larger maor complex molecule is larger
- entropy of ionic solid with a weaker force is larger
- entropy of solute in solution is greater than the pure solute
spontaneous reaction
- change in G is less than 0
- E of cell is greater than 0
- K is greater than 1
characteristics of enthalpy
- if change in H is less then 0, then exothermic
- if change in H is greater then 0, then endothermic
first law of thermodynamics
energy/mass of the universe is constant
second law of thermodynamics
the entropy of the universe is always increasing
third law of thermodynamics
entropy of a pure and perfect crystal at absolute zero is zero
in line notation which elements go on the left and which on the right
oxidation is on left and reduction is on the right
spontaneous reaction
one that occurs without ongoing outside intervention such as work and external force
enthalpy
sum of internal energy of a system and product of its pressure and volume
entropy
thermodynamic function with the number of energetically equivalent ways to arrange the components of a system to achieve a particular state
standard entropy change for a reaction
change in entropy for process in which all reactants and products are in standard states
allotropes
an element that can exist in two or more forms
reversible reaction
reaction that achieves theoretical limit with respect to free energy
irreversible reaction
do not achieve the theoretical limit of available free energy
electrical current
flow of electrical current
electrochemical cell
device in which the generation of electricity through redox reactions occur
reduced on right and oxidized on left
half-cell
one half of an electrochemical cell where either oxidation or reduction occurs
electrodes
conductive surfaces through which electrons can enter or leave half-cells
cell potential
measure of overall tendency of the redox reaction to occur spontaneously
anode
electrode where oxidation occurs
cathode
electrode where reduction occurs
salt bridge
device used that connects half-cells to give the counterions a pathway to continue motion
standard electrode potential
where each half-cell has its own potential
standard hydrogen electrode (SHE)
half-cell electrode that is normally chosen to have a potential of zero (platinum)
