lecture 1 Flashcards
what is the study of electrochemistry
study of ions in solution + their application
how can we see if smt can function as a battery
if the elements can accept / release electrons
how can we check a chemical reaction is occuring
look at the chemical potential at both sides of the equation
what is G
gibbs free energy
needs to be - to be spontaneous
what is G at equilibrium
0
what is Ecell
it means the electrochemical potential ofa cell
what is a cell
a cell is the system
both solutions
in separate beakers
with salt bridge and metals connecting them
when an ion is put into a solution what changes??
the chemical potential of the solution
what does henrys law do
judges the chem potential against a reference chemical potential
based on amount of solvent
what is the chem potential of an ion symbol
long u B
what is the chem potential of an ion in solution
long u B*
what is B in henrys law
the ion u are putting into a solution
what is RT ln() in henrys law
the correction
aka the difference between the chem potential of the ion and the chem potential of the ion in solutions
in henrys law what is rthe correction
RTln(PB/PB*)
what does PB/PB* mean in the henrys law correction
partial pressure in respect to partial pressure of smt else
how can we get PB
we need to KB (empirical constant - given)
and XB = mole fraction
what is long u B *-
chemical potential of reference state
its a circle with a line in the middle
aka state.
in thermo dynamics,, whats the most conventient way to work in
working in ideal conditions
when is ideal behaviour difficult to maintain
when an ion has a strong charge
the chem potential of an ion, B, can be given by whatg
the chem potential of reference state
+ RTln(XB)
what is aB
activity
an ion with a strong charge may have some activity on the solution or its environment
what does aB equal
YB XB
aka activity coefficient x mole fraction
chem potential when given activity coefficient and mole fraction
uB = uB *- + RTln(aB)
what is uB *- again
the chem potential of a reference state
what is molality
bB
number of moles / mass of solvent
in kg
nA/ mA (kg)
units cancel out!! we can take the ln of smt unitless which is good
replacing henry law with molality instead of mole fraction
uB = uB- + RTln(bB/b-)
the smaller the molality, bB
the more stable the solution?? bc ur taking ln(0) which gives a (-) meaning rhe rea is spontaneous and gives the more stable product.
aB equation when replacing xB with molality
aB = YB (bB/b*-)
what are deviations from ideality usually captured by
the activity coefficient Y
