Formulas Flashcards
What is the equillibrium law?
Kc = [A]^a[B]^b (products)
[C]^c[D]^d} (reactants)
Describe DYNAMIC EQUILIBRIUM
DYNAMIC EQUILIBRIUM occurs when the concentrations of the product and reactants remain constant and the rate of the forward reaction is equal to the rate of the backwards reaction.
What are the units of K to the 0th order?
M/s
What are the units of rate constant K to the 1st order?
1/s
What are the units of rate constant K to the 2nd order?
1/s*M
What happens to the rate of reaction if the concentration of reactants are increased?
The rate of reaction increases.
What happens when you increase the surface area of a reactant. E.G. Big pieces vs several smaller pieces
A big piece will slow the rate of reaction while smaller pieces will increase the surface area and increase the rate of reaction.
What happens to the rate of reaction if you lower or raise the temperature of the solution?
An increased temperature will increase the rate of reaction while a decreased temperature will slow the rate of reaction.
What happens if you introduce a catalyst to a reaction?
The rate of reaction will increase and the catalyst will not be consumed by the reaction (it will remain unchanged in concentration).
What is the format for a rate law?
R= k[A]^x[B]^y
How do you determine the order of reactants in a rate law?
You compare concentrations between reactants [A] and [B] and their rate laws. To find [A] you would look when two experiments show [B]’s concentration as remaining the same. From there you see what factor the concentration of [A] has changed by i.e. 1.00 to 3.00 would = 3. And the factor the rate of reaction has changed by I.e. 0.01M/s -> 0.09M/s = 0.09/0.01 = 9. Therefore, 3 to to the power of 2 equals 9. So we know [A] would be to the Second order written as [A]^2. To find the order of [B] we would would follow the same steps but this time with the data indicating a constant concentration of [A].
How to find the overall order of rate law?
Add the orders of all the reacts. Example if [A]^2 and [B]^1, the overall order would be 3.
What is a reactant quotient?
A reactant quotient follows the same formula as Kc but is only the equilibrium constant if it is equal to Kc.
Qc > Kc
There are more products than reactants and the reaction would have to move right to left to reach equillibrium.
Kp
Equillibrium constant in terms of pressure
Kc
Equilibrium constant in terms of concentrations
Qc < Kc
Reaction requires more reactants to move left to right and reach equlibrium
Kc = Qc
System is at equlibrium. Concentrations of products and reactants are equal and rate of reaction are the same for products and reactants
Rate determining step
The rate determining step (RDS) is the slowest in a multistep reaction, requires a larger activation energy (Ea) and limits the over all rate thus determining the rate law.
Which way will an Exothermic Reaction equilibrium action procede?
Products to reactants
Reverse
Right to Left
Which way will an endothermic reaction proceed?
Reactants to products
Forward
Left to right
Consider the EXOTHERMIC reaction: 4NH3(g)+5O2(g)⇌4NO(g)+6H2O(l)
What will happen if you remove O2 gas
Removing a reactant will cause the reaction to shift to the left to produce more O2
Consider the EXOTHERMIC reaction: 4NH3(g)+5O2(g)⇌4NO(g)+6H2O(l)
What will happen if you add H2O (liquid) to the container?
No change because H2O is in liquid state and adding some more will not change the concentration
Consider the following EXOTHERMIC reaction: 4NH3(g)+5O2(g)⇌4NO(g)+6H2O(l)
What will happen if you increase the volume thus decreasing the pressure?
Shift left. Decreasing the pressure (increasing the volume) will cause the system to shift to the side with the most moles of gas. In this case, the reactant side has 9 and the product side has 4.
