Equations
Rate constant unit formula
1/(M(overall order-1)(time))
The rate of appearance for C in the rxn
A + B ----> C
(delta)[C]/(delta)t
Description of rate intermediates?
Formed and then consumed
Numerator & denominator of equilibrium expression
Products/Reactants
(NEVER include solids or liquids)
a) acids
b) bases
a) donate protons (H+)
b) accept protons (H+)
Ea(rev) equation
Ea(rev) = Ea(fwd) - deltaH
general rate law for
A + B ---> C
Use x & y for the orders
rate = k[A]x[B]y
Slowest step is referred to as?
rate-determining step or rate-limiting step
What to do when the rxn direction is not known in an equilibrium ICE table?
Compare Q & K to see which direction the rxn will proceed
How do you get the pH from the hydronium concentration and then get back to hydronium?
pH = -log[H3O+]
[H3O+] = 10-pH
Two-point form of the Arrhenius Equation
ln(k1/k2)=(-Ea/R)(1/T1-1/T2)
[A]t denotes?
reactant concentration remaining (not used up) at time t
How does a catalyst affect the Ea?
Catalyst lowers the Ea
Heat will be added to the reactants side
Strong acids and bases diss.?
They dissociate 100%
The equation used to relate Kc & Kp
Kp=Kc(RT)(delta)n
What is the integrated rate law for 1st order?
Bonus!
Zero & 2nd order?
ln[A]=ln[A]0-kt
Bonus:
0: [A]=[A]0-kt
2: 1/[A]=1/[A]0+kt
The # of humps in an energy diagram depends on?
Which direction will the rxn proceed based on the comparison of Q & K?
a) Q=K
b) Q<K
c) Q>K
a) at equilibrium
b) right (towards products)
c) left (towards reactants)
pH + pOH =?
14.00
% HA dissociation equation?
% = [HA]diss./[HA]init*100
describe how the half-lives of zero, 1st, and 2nd orders behave?
zero: 1/2 life dec.
1st: 1/2 life remains the same
2nd: 1/2 life inc.
3 steps for validating a mechanism?
1. elementary steps add up to overall balanced equation
2. mechanism correlates w/ the observed rate law
3. elementary steps are no more than bimolecular
Algebraic manipulations to Kc or Kp
1) reverse the rxn
2) multiplication to a rxn
3) how to get Koverall
1) inverse of K (1/K)
2) # multiplied is now a power of K (K#)
3) multiply K values together to get Koverall
If we inc. the hydronium concentration what happens to the Ka and the pH?
Ka inc. (Ka=[H3O+][A-]/[HA])
pH dec. (the more acidic the lower the pH)