Gen Chem 3 Values and Their Meanings

Question 1

K is 25. What does that tell you about the reaction?

Answer 1

The reaction FAVORS PRODUCTS.
If it was at equilibrium, there would be more products than reactants.

Question 2

K is 8.27 x 10^12. What does that tell you about the reaction?

Answer 2

The reaction FAVORS PRODUCTS.
If it was at equilibrium, there would be more products than reactants.

Question 3

K is 0.491 What does that tell you about the reaction?

Answer 3

The reaction FAVORS REACTANTS
If it was at equilibrium, there would be more reactants than products

Question 4

K is 2.69 x 10 ^ -5 What does that tell you about the reaction?

Answer 4

The reaction FAVORS REACTANTS
If it was at equilibrium, there would be more reactants than products

Question 5

You calculate that K is -58.4 What does that tell you about the reaction?

Answer 5

Trick question. It tells you that you don’t understand chemistry, because K cannot be negative!

K is a ratio of product amounts over reactant amounts, and you can’t have a negative amount of a chemical!

Question 6

Q is 300 What does that tell you about the reaction?

Answer 6

Not much. All it says is that you have a lot more products present now than reactants.

But you can’t figure out which way the reaction will shift b/c you don’t know K.

Question 7

Q is 0.1111 What does that tell you about the reaction?

Answer 7

Not much. All it says is that you have more reactants than products present right now.

But you can’t figure out which way the reaction will shift b/c you don’t know K

Question 8

Q = 750 and K = 200 What can you say about the reaction?

Answer 8

Because K is bigger than 1, the reaction generally FAVORS PRODUCTS.

But because Q is bigger than K, it must SHIFT TO FORM REACTANTS in order to reach equilibrium.

Question 9

Q = 5267 and K = 9000 What can you say about the reaction?

Answer 9

Because K is bigger than 1, the reaction generally FAVORS PRODUCTS.

Because Q is smaller than K, it must SHIFT TO FORM PRODUCTS in order to reach equilibrium.

Question 10

Q = 0.00543 and K = 0.0654 What can you say about the reaction?

Answer 10

Because K is less than 1, the reaction generally FAVORS REACTANTS

But because Q is smaller than K, it must SHIFT TO FORM PRODUCTS in order to reach equilibrium.

Question 11

Q = 650 and K = 8.33 x 10^ -5 What can you say about the reaction?

Answer 11

Because K is less than 1, the reaction generally FAVORS REACTANTS

Because Q is bigger than K, it must SHIFT TO FORM REACTANTS in order to reach equilibrium.

Question 12

Q = 27.6 and K = 27.6 What can you say about the reaction?

Answer 12

Because K is bigger than 1, the reaction generally FAVORS PRODUCTS.

Because Q = K, the reaction is currently AT EQUILIBRIUM

Question 13

ΔG = 85.0 kJ/mol What can you say about the reaction?

Answer 13

Because ΔG is positive, given the current conditions, the reaction must SHIFT to form REACTANTS in order to reach equilibrium.

Question 14

ΔG = 0.250 kJ/mol What can you say about the reaction?

Answer 14

Because ΔG is positive, given the current conditions, the reaction must SHIFT to form REACTANTS in order to reach equilibrium.

Question 15

ΔG-standard = 155 kJ/mol. What can you say about the reaction?

Answer 15

Because ΔG-standard is positive, the reaction generally FAVORS REACTANTS. If it ever reaches equilibrium, there will be more reactants present than products.

Question 16

ΔG-standard = 0.617 kJ/mol What can you say about the reaction?

Answer 16

Because ΔG-standard is positive, the reaction generally FAVORS REACTANTS. If it ever reaches equilibrium, there will be more reactants present than products.

Question 17

ΔG = - 376 kJ/mol What can you say about the reaction?

Answer 17

Because ΔG is negative, given the current conditions, the reaction must SHIFT to form PRODUCTS in order to reach equilibrium.

Question 18

ΔG = - 0.444 kJ/mol What can you say about the reaction?

Answer 18

Because ΔG is negative, given the current conditions, the reaction must SHIFT to form PRODUCTS in order to reach equilibrium.

Question 19

ΔG-standard = -500 kJ/mol. What can you say about the reaction?

Answer 19

Because ΔG-standard is negative, the reaction generally FAVORS PRODUCTS. If it ever reaches equilibrium, there will be more reactants present than products.

Question 20

ΔG-standard = -0.246 kJ/mol What can you say about the reaction?

Answer 20

Because ΔG-standard is negative, the reaction generally FAVORS PRODUCTS. If it ever reaches equilibrium, there will be more reactants present than products.

Question 21

ΔG = 0 kJ/mol What can you say about the reaction?

Answer 21

It is at equilibrium.

Question 22

ΔG-standard = 0 kJ/mol. What can you say about the reaction?

Answer 22

If it ever reached equilibrium, it would have equal amounts of reactants and products. It does not FAVOR either one.

Question 23

E = 5.25 V What can you say about the reaction?

Answer 23

Because E is positive, given the current conditions, the reaction will SHIFT to form PRODUCTS.

Question 24

E = 0.355 V What can you say about the reaction?

Answer 24

Because E is positive, given the current conditions, the reaction will SHIFT to form PRODUCTS.

Question 25

E = -1.77 V What can you say about the reaction?

Answer 25

Because E is negative, given the current conditions, the reaction will SHIFT to form REACTANTS.

Question 26

E = -3.18 V What can you say about the reaction?

Answer 26

Because E is negative, given the current conditions, the reaction will SHIFT to form REACTANTS.

Question 27

E-standard = 4.81 V What can you say about the reaction?

Answer 27

Because E-Standard is positive, the reaction generally FAVORS PRODUCTS.

Question 28

E-standard = 0.813 V What can you say about the reaction?

Answer 28

Because E-Standard is positive, the reaction generally FAVORS PRODUCTS.

Question 29

E-standard = -2.81 V. What can you say about the reaction?

Answer 29

Because E-Standard is negative, the reaction generally FAVORS REACTANTS.

Question 30

E-standard = -0.194 V What can you say about the reaction?

Answer 30

Because E-Standard is negative, the reaction generally FAVORS REACTANTS.

Question 31

E = 0 V. What can you say about the reaction?

Answer 31

The reaction is at equilibrium.

Question 32

E-standard = 0 V What can you say about the reacftion?

Answer 32

If the reaction ever reached equilibrium, it would have equal amounts of reactants and products. Neither one is FAVORED.

Question 33

What sort of values can K be?

Answer 33

Any positive number.

Question 34

What sort of values can Q be?

Answer 34

Zero or any positive number.

Question 35

What sort of values can ΔG be?

Answer 35

ΔG can be any real number.

( Just so you have a reference for “does my answer make sense”, I typically write problems where it is between -2500 kJ/mol and 2500 kJ/mol, but there’s no real limit in either direction. )

Question 36

What sort of values can ΔG-standard be?

Answer 36

ΔG-standard can be any real number.

( Just so you have a reference for “does my answer make sense”, I typically write problems where it is between -2500 kJ/mol and 2500 kJ/mol, but there’s no real limit in either direction. )

Question 37

What sort of voltages can E be?

Answer 37

E can be ANY real number.

(To get large magnitudes of E, you need to connect together multiple electrochemical cells, but they ARE certainly possible. In the questions I write, E is typically between -4.00 V and 4.00 V but those are not real cutoffs. )

Question 38

What sort of voltages can E-standard be?

Answer 38

E-standard can be ANY real number.

(To get large magnitudes of E-standard, you need to connect together multiple electrochemical cells, but they ARE certainly possible. In the questions I write, E is typically between -4.00 V and 4.00 V but those are not real cutoffs. )

Question 39

What thing(s) should you compare K to?

Answer 39

K should be compared to 1 to figure out what is FAVORED

K should be compared to Q to figure out which way it will SHIFT

Question 40

What thing(s) should you compare Q to?

Answer 40

You should compare Q to K to figure out which way the reaction SHIFTS

Question 41

What thing(s) should you compare ΔG to?

Answer 41

You should compare ΔG to zero to figure out which way the reaction will SHIFT.

Question 42

What thing(s) should you compare ΔG-standard to?

Answer 42

You should compare ΔG-standard to zero to figure out what the reaction FAVORS.

Question 43

What thing(s) should you compare E to?

Answer 43

You should compare E to zero to figure out which way the reaction will SHIFT.

Question 44

What thing(s) should you compare E-standard to?

Answer 44

You should compare E-standard to zero to figure out what the reaction FAVORS.

Question 45

What values can pH be?

Answer 45

pH can be any number. It’s USUALLY between -1 and 15, but those aren’t hard cutoffs.

Question 46

What values can pOH be?

Answer 46

pOH can be any number. It’s USUALLY between -1 and 15, but those aren’t hard cutoffs.