chem1a 36 periodic table

"electron configuration notation"
Ex. Be ... [He]2s${}^2$   Mg ... [Ne]3s${}^2$
"effective nuclear charge" trend <-> Ionization Energy trend

chem1a 35

$\Sigma$(ejected e${}^-$) /(atom|mol) = Energy injected /(atom|mol)

5 11 1 36 review

"cofactor" catalyst helper
electrolytic <-> galvanic

Lec 36 | MIT 5.111 Principles of Chemical Science, Fall 2005

5 11 1 35 catalyst

catalyst 'stabilize' or lower transition state (activated complex)
affects rate, but no change in thermodynamics
inhibitor <-> catalyst
heterogeneous ex. metal solid works as catalyst for a gass
reactants@chemistry -> substrates@biochemistry
'active site' ES complex product P
! dynamics <-> kinetics
Michaelis–Menten K${}_M$をv${}_{max}$とその半分を与える濃度から実験的に求めることができる(wikipedia)
peptide bond cleaved protease

Lec 35 | MIT 5.111 Principles of Chemical Science, Fall 2005

5 11 1 34

Plot $\ln$ 'k' - inverse Temperature ... intercept 'A' the facor A| pre-exponential factor
slope ... Energy of activation / R "reaction coordinate" diagram Potential Energy-Reaction Coordinates
Big Activation Energy -> more sensitive to temperature change
$\Delta$H = $\Delta$E + $\Delta$(PV) (1-2% for gas 0% for solid,liquid)
if 1st step in 2 step RxN is exothermic, raising temperature might slow the overall reaction.

Lec 34 | MIT 5.111 Principles of Chemical Science, Fall 2005

UCB chem1a lec 34 all aglow: light energy

bolic acid B(OH)${}_3$ "roach prufe"
light different wavelength <-> momentum different mass balling ball pachinko ball
1 eV = 1240 nm = 242  THz

5 11 1 33 Reaction Mechanism

k${}_{observed}$ k - [reactants] relationship k - [products] relationship
 -> come up with appropriate mechanism to fit the experimental relationships
[NO]${}^2$ [O${}^2$]

step 1. NO + NO ⇔ N${}_2$O${}_2$ -(k1)-> <-(k-1)-
 rate${}_{forw}$ = k${}_1$[NO]${}^2$ bimolecular
 rate${}_{rev}$ = k${}_{-1}$[N${}^2$O${}^2$] monomolecular
step 2.  O${}_2$ + N${}^2$O${}^2$ -(k2)-> NO${}_2$ + NO${}_2$
 rate = k${}_2$[O${}_2$][N${}^2$O${}^2$]
 (*) overall rate of NO${}_2$ formation = 2 k${}_2$[O${}_2$][N${}^2$O${}^2$]
you need to get rid of intermediate [O${}_2$][N${}^2$O${}^2$]
net formation of [O${}_2$][N${}^2$O${}^2$] = k${}_1$[NO]${}^2$ (formed) - k${}_{-1}$[N${}^2$O${}^2$] (decomposed) - k${}_2$[O${}_2$][N${}^2$O${}^2$] (consumed) = 0 @ equilibrium
[N${}^2$O${}^2$] (k${}_{-1}$ + k${}_2$[O${}_2$]) = k${}_1$[NO]${}^2$
 (*) = 2k${}_1$k${}_2$[NO]${}^2$[O${}_2$] / (k${}_{-1}$ + k${}_2$[O${}_2$]) !!! not consistent
fast first step(also reversible) & slow second step. 'rate determining step'
first step @ quasi-equilibrium during the reaction
[NO][Br${}_2$]

Lec 33 | MIT 5.111 Principles of Chemical Science, Fall 2005