Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
44 Cards in this Set
- Front
- Back
Half life calculation for first order |
T 1/2= 0.693/k Ln [A]=-kt +ln[A]0 |
|
List strong acids |
HCl, H2SO4, HNO3, HClO4 All others are weak with intermediates, how do |
|
With intermediates, how do you tell which step is the rate determining step with graphs? |
One with the highest energy transition state |
|
At equilibrium: |
-rate of the forward and reverse reactions are equal -concentrations have stopped changing BUT NEVER EQUAL!!! |
|
pH vs. pKa |
pH -measures the concentration of H3O in a solution -describes solution pKa- is a measure of the strength on an acid -describes acid |
|
Archenius Equation: Calculating Eact graphically |
ln(k)= ln(A)+(-Eact/R)(1/T) y =b + m x R=8.314 M=(-Eact/R) |
|
Calculating Ka and Kb for conjugate pair |
(Ka)(Kb)= 1*10^-14 |
|
Half life for zero order |
[A]=-Kt+[A]0 t1/2- [A]0/2k |
|
Old DeltaG formula |
DeltaG=deltaH-TdeltaS |
|
Calculating Kat another temp |
ln (K1/K2= -Eact/ R((1/T1)-(1/T2)) R=8.314 |
|
At 25 degrees C, Kw= 1*10^-4 so, |
(Ka)(Kb)=14 pKa+pKb=kw |
|
Equilibrium constant and deltaG are related by: |
DeltaG= -RT ln(k) DeltaG @same temp R=8.314 T=temp of (k) k=Value of ka at t |
|
pH and POH equations |
pOH=-log [OH-] |
|
a reaction would be slightly thermodynamically favorable, but occur very quickly if it has a ___ |
-small negative Delta G -Low activation energy |
|
A reaction would be very thermodynamically favorable, but occur very slowly if it has a ___ |
-Negative DeltaG -High activation energy |
|
Weak acids |
-donate some protons - Dissociates sometimes -ionizes some |
|
Strong acids |
-Donates all protons -Dissociates completely -ionizes completely |
|
Proceeds to equal |
Implies a system that has never been at equilibrium responding to a stress and re-reaching equilibrium |
|
How to find Activation energy for an intermediate reaction |
difference between reactants and the energy of the highest transition state |
|
inc in value of k=??? When does K change and when does it not change? |
-favor in the products -K does not depend on inc. or dec. of products or reactants but does depend on temp |
|
Not an actual acid |
-Donates nothing -dissociates nothing -ionizes nothing |
|
Ka and Kb represents |
Ka= Adid strength Kb=base strength |
|
What range is 1 stonger weak 2 weaker weak and 3 really weaker weak acids in |
110^-2 2 10^-8 3 10^-8 |
|
large Ka vs small Ka |
inc. Ka, stronger acid strong acids have infinite #s ~~~~~~~~~~~~~~~~~~~~~~~~~ Dec. Ka, weaker- Regular #s |
|
pKa |
is often used to indicate the acid strength instean of Ka (P) means -log |
|
Higher the Ka the___ the pKa The lower the pKa, the ___ the acid |
lower lower |
|
strength of base is measured by ___ |
its desire to accept protons -stronger base--->greater desire |
|
CONJUGATE OF A WEAK ACID WILL ALWAYS BE A WEAK BASE |
vice versa |
|
can calculate the concentration depending on 3 things |
1. whether the solute is an acid/ base 2. Whether it is a strong/weak (base or acid) 3. Concentration of the base/ acid |
|
When an alkali metal is dissolved in water the solution is ___ |
basic |
|
when the HCl salt is dissolved in H2o the solution is ___ |
acidic |
|
When is a metal ion an "Acid"? |
When it has a +2 or +3 charge |
|
small x assumptions |
assuming a small number can just be x as long as it is lower than 5% |
|
list the strong base |
OH- -all others are weak |
|
when an acid is added to water |
-inc H3O+, shift to left -dec. in OH- [H3O+]> 1*10^-7, [OH-]<1*10^-7 |
|
adding base to water |
-bases inc. [OH-} -Shifts to the left -[H3O+]<1*10^-7, [OH-]> 1*10^-7 |
|
How to calculate K from the graph |
Find numbers on graph when it stops charging and fill into equation |
|
DeltaG=0 |
-at breaking point -not favorable to go in either direction -system is already at equilibrium |
|
DeltaG>o |
-Non-spontaneous -fav. in reverse reaction |
|
DeltaG<0 |
-spontaneous -Fav in forward reaction |
|
In all aqueous solutions: 1. [H3O+][OH]=??? 2. pH=pOH=??? |
1. =14 2. =7 |
|
The pH depends on the same three things that [H3O+] and [OH-] depend on: |
1. whether the solute was and acid or a base 2. whether it was a strong or weak acid/base 3. The concentration of the acid/base |
|
General statement: The rate law for each elementary step in a mechanism can be predicted from equation for that step |
Note: This is not true for overall equations/reactions |
|
No reaction or very little reaction, would be observed for reactions that have ___ |
-Positive DeltaG's -Really high activation energies |