ch 6

Question 1

equilibrium

Answer 1

when the forward reaction rate = the backward reaction rate
@ equilibrium, the amount of react and product remain constant

Question 1

equilibrium expression

Answer 1

kc = [products]^n / [reactants]^n

Question 2

pressure equilibrium expression

Answer 2

kp = (Pproducts)^n/(Preactants)^n

Question 3

reaction between Kc and Kp

Answer 3

Kp=Kc(RT)^delta n
delta n = products moles — reactants moles

Question 4

what does a k»1 mean

Answer 4

reaction is product-favored
add to product side

Question 5

what does K«1 mean

Answer 5

reaction is reactant-favored
add to reactant side

Question 6

solving for equilibrium concentration values (step-by-step)

Answer 6

use an ice chart
- add to side with initial value 0 OR look at K-value to see shift in equilibrium
- use x=(-b+- sqrt (b^2) - 4ac )/2a to solve for x

Question 7

Manipulating K
K-value when original equation is multiplied by a #
Ex:
N2O4 <—> 2NO2. K=0.212
2N2O4<—> 4NO2. K=???

Answer 7

raise K to the Number you multiplied by
K=(0.212)^2

Question 8

Manipulating K
What is K value when you have a reverse reaction of the original reaction
Ex:
N2O4 <—> 2NO2. K=0.212
2NO2 <—> N2O4. K=???

Answer 8

K= 1/0.212
put K under 1

Question 9

Manipulating K
two equations added together to form a third reaction —> what is K value

Answer 9

K3 = (K1)(K2)
multiply k values of first two equations

Question 10

exothermic
also what happens to K when u increase heat

Answer 10

releases heat as a product
reactant —> product + heat
if you increase heat you decrease K
reaction shifts to left

Question 11

Endothermic
what happens when you increase heat

Answer 11

absorbs heat as a reactant
reactant + heat —> product
increase heat = increase K
shift to right

Question 12

what is the reaction quotient

Answer 12

Q
indicated reaction concentration ratio at any point in reaction
comparison to K tells us which way the reaction needs to shift until equilibrium is reached

Question 13

Q=K

Answer 13

reaction is at equilibrium

Question 14

Q<K

Answer 14

reaction will shift to the right until equilibrium is reached

Question 15

Q>K

Answer 15

reaction will shift to the left until equilibrium is reached

Question 16

Le Chateliers Principle

Answer 16

when a stress is added to a reaction at equilibrium, it will shift to a certain direction until equilibrium is reached again

Question 17

what happens when u remove a gaseous product in a reaction at equilibrium

Answer 17

reaction shifts to the right
(Q<K)

Question 18

what happens when you add a gaseous product that is at equilibrium

Answer 18

reaction shifts to left
(Q>K)

Question 19

what happens when you add HCl to the following reaction:
Mg(OH)2 (s) <-> Mg^2+ + OH-

Answer 19

shifts to the right because H+ forms water with OH- so you are basically removing product

Question 20

volume and pressure relationship

Answer 20

inverse relationship
when you reduce volume pressure increases
when you increase volume pressure decreases

Question 21

what happens when you reduce volume

Answer 21

reaction shifts to side with less moles of gas (pressure is high so it wants to go to side with less pressure)

Question 22

what happens to reaction when mol reactant= mol products and there is a change in volume

Answer 22

nothing
no shift