Q v K
Equilibrium
Le Chateliers
Ksp
Equilibrium constant
100
If the system is at equilibrium Q <=> K?
=
100
At what time is the system at equilibrium? 0, 20, 21, or 60
What is 60 seconds?
100
This stress only affects equilibrium reactions with at least one gas
What is a pressure change?
100
Write the Ksp expression for the following dissociation: Mg(OH)2 (s)
Ksp= [Mg2+] [OH-]2
100
If K>1, what side of the equation is favored? Reactants, Products, or neither?
What are Products?
200
If the system is shifting to the left Q __ K
What is >
200
Which system shows equilibrium? 1-2- or 3
What is reaction system 2?
200
Fe3+ + SCN- <------> FeSCN2+ If I added Fe3+ to the system the reaction would favor....
What are the products?
200
If the Ksp= 1.8x10-11 for Mg(OH)2 what write the mathematical equation to solve for the molar solubility. DO NOT SOLVE
1.8x10-11= 4s3
1.8x10-11/4 = s3
(1.8x10-11/4)1/3= s
200
This is the only stress that can change the Kc value
What is temperature?
300
A + 2B --> AB2 Kc= 100
If a vessel has [A]= .1M [B]=.2 and AB2 is .5, is the system at equilibrium or will it shift to the left or right?
What is shift to the LEFT?
.5/[(.2^2)x.1]= 125 100<125; K<Q
300
This addition of this will speed up BOTH the rate of the forward AND reverse reactions, so does not get included in the equilibrium expression?
What is a catalyst?
300
N2O4 <---> 2NO2 ^H= +58 kJ In order to favor the products the temperature would need to...
What is increase?
300
What are the units of molar solubility in a Ksp equation?
mol/L
300
When flipping an equation, the Kc
a. is multiplied by -1
b. is held constant
c. is raised to the -1 power
C. raising to the -1 is the reciprocal
400
A + B <---> C + D
A 32 L flask has 16 mol of A and B and 32 moles of C, and D. If Keq is 5.5, determine which way the reaction is running
To the right!
K> Q 5.5> 4 1x1/(.5x.5)=4
400
These two states of matter are not included in equilibrium expressions and do not affect the constant.
What are solids and liquids?
400
5A (g) + 9D (l) <---> 6E (aq) + 3G (g) If we increase the volume, which way will the reaction shift?
What is shift to the LEFT?
400
What solid will have more ions in solutions?
FeCO3
400
H2 + F2 <---> 2HF Initially, 10 mol H2 and 6 mol F2 are in an evacuated 2L flask. At eq, 5 mol HF are present. Write the initial row for the ICE table
Star= 5
? = 3
??= 2.5 NEED TO USE CONCENTRATION
mol/L
500
D. Q= 1,851 > K
K<Q shifts to the left, so products decrease
500
4A (g) + 2B (g) <---> 3C (g) What is the equilibrium expression, Kp?
MUST USE () for P
Kp = (Pc)3 / (PB)2(PA)4
500
If the temperature of an exothermic reaction increases, what happens the Keq?
Shift to the left (reactants)
K<1, so you are making the K value smaller/decreases
500
AgBr has a Ksp of 5x10-13. If a student adds NaBr to a test tube with AgBr, what happens to the molar solubility?
What is decreased?
Remember Ksp is a constant, only changed by temperature
500
N2 + 3H2 <---> 2NH3
Initially, 12 mol NH3 are put in an evacuated 2L flask. At equilibrium, the concentration of N2 is 1 M. What is the Keq?
0 0 12/2=6
+x +3x -2x
1 3 4 4^2/(1x3^3)
16/27= .59