5 11 1 32 kinetics continued & mechanisms

Becquerel = [s^-1]
@equilibrium ... rates of forward RxN and the rates of backward RxN are the same
A + B ⇔ C + D
         -> @ k${}_{1}$[A][B]
         <- @ k${}_{-1}$[C][D]
K = [C] [D] / [A][B]
then @ equilibrium k${}_{1}$ / k${}_{-1}$ = K
"elementary reaction" ... rate law can be written as eq. " the reaction order, the molecularity and the stoichiometric coefficient are the same"
"Molecularity"

Lec 32 | MIT 5.111 Principles of Chemical Science, Fall 2005

UCB chem1a lec 33

cathode reduction acceptor
anode oxidation donner
Zn around Fe pipe ... sacrificial electrode metal

CH${}_4$ + O${}_2$ -> CO${}_2$ + H${}_2$O ... $\Delta$G${}^0$ = -818 kJ/mol
$\Delta$G std. state $\Delta$G = $\Delta$G${}^0$ + RL$\ln$Q $\frac{(1)}{{(1)}^2(1)}$ $\Delta$G = $\Delta$G${}^0$
$\Delta$G equil $\Delta$G = $\Delta$G${}^0$ + RL$\ln$Q = 0

5 11 1 31 kinetics

labile ... high rate
Rates of RxN = f (temperature ,concentration ,catalysts ,nature of material ,mechanism)
Rate Law 'k' rate constant <-> 'K' equilibrium constant
 elementary reactions <-> RxN with mechanisim (steps)
'order' 'half-life'
 

Lec 31 | MIT 5.111 Principles of Chemical Science, Fall 2005

UCB chem1a lec 32

Energy,Enthalpy,Entropy "keeping track of " something invisible

Physical (#chemical) change
 Heat transfer = q =q m C${}_p \Delta$T
 Melting and Vaporize


Chemical bonds
 H:Enthalpy
 H--:Exothemic
 H++:Endothermic (biologist call this "high energy"bond meaning highly reactive)

$\Delta$H
 Bond dissociation - (atoms) , - of formation (elements) #2 reference point

$\Delta$G${}^0$
 $\Delta$G${}^0$ = - R T $\ln$ K
 $\Delta$G${}^0$ = - n F $\Delta$E${}^0_{cell}$
 $\Delta$G${}^0$ = max work  ?P$\Delta$V?

E${}^0$ standard 'reduction' potential

UCB chem1a lec 31 the Sun

plasma ... the 4th states of matters
positron ... positive electron

UCB chem1a lec 30 Batteries

oxidize ... さびる、イオンになる、単体から化合物、-> +∞
reduction ...  戻る。単体になる。-> -∞
$\Delta$G = - n F $\Delta$E ... 'Maximum' work E自体は'n'つまり何価のとりひきかは関係しない。i.e. 端子間電圧を見るときには'n'を見ていない。

5 11 1 30

energy levels are flipped @tetrahedral ligands configuration relative to @octahedral case
High spin system example [Fe(H${}_2$O)${}_6$]${}^{3+}$ ... d${}^5$ system = t${}_{2g}^3$ e${}_g^2$ Crystal Field Splitting Energy = 0 Weak field ligands
Low spin system example [Fe(CN)${}_6$]${}^{3+}$ ... d${}^5$ system Strong Field #Energy Gap > Pairing Energy
"Transition Complex" "cofactor"
paired -> diamagnetic, unpaired -> paramagnetic

Lec 30 | MIT 5.111 Principles of Chemical Science, Fall 2005