Reactivity 1.4

Question 1

In terms of spontaniety, describe a process which requires work to be done to make it happen

Answer 1

Non-spontaneous

Question 2

In terms of spontaniety, describe a process which does not require work to make it happen

Answer 2

Spontaneous

Question 3

TRUE or FALSE: All exothermic processes are spontaneous

Answer 3

False

Question 4

TRUE or FALSE: All endothermic processes are non-spontaneous

Answer 4

False

Question 5

TRUE or FALSE: Spontaneous processes can be exothermic or endothermic

Answer 5

True

Question 6

TRUE or FALSE: The standard entropy of an element is zero

Answer 6

False

Question 7

In terms of disorder, describe what happens when entropy is positive

Answer 7

Disorder increases

Question 8

In terms of disorder, describe what happens when entropy is negative

Answer 8

Disorder decreases

Question 9

State the units for enthalpy

Answer 9

kJ K⁻¹ mol⁻¹

Question 10

State the units for entropy

Answer 10

J K⁻¹ mol⁻¹

Question 11

State the units for gibbs free energy

Answer 11

kJ K⁻¹ mol⁻¹

Question 12

State the symbol for entropy

Answer 12

S

Question 13

State the symbol for gibbs free energy

Answer 13

G

Question 14

State the symbol for enthalpy

Answer 14

H

Question 15

State the name of the measurement with the symbol H

Answer 15

Enthalpy

Question 16

State the name of the measurement with the symbol S

Answer 16

Entropy

Question 17

State the name of the measurement with the symbol G

Answer 17

Gibbs free energy

Question 18

State the name of the measurement of dispersal of matter and energy in a system

Answer 18

Entropy

Question 19

What does entropy measure?

Answer 19

The dispersal of matter and energy in a system

Question 20

Describe how entropy changes if dispersal of matter and energy in a system increases

Answer 20

Entropy increases

Question 21

Describe how entropy changes if dispersal of matter and energy in a system decreases

Answer 21

Entropy decreases

Question 22

Describe how the dispersal of matter and energy in a system changes if entropy is positive

Answer 22

The matter and energy becomes more dispersed OR increased amount of disorder

Question 23

Describe how the dispersal of matter and energy in a system changes if entropy is negative

Answer 23

The matter and energy becomes less dispersed OR decreased amount of disorder

Question 24

Describe how the entropy of a system changes as temperature increases

Answer 24

Entropy increases

Question 25

Describe how the entropy of a system changes as temperature decreases

Answer 25

Entropy descreases

Question 26

Predict the sign of entropy during melting

Answer 26

Positive

Question 27

Predict the sign of entropy during boiling

Answer 27

Positive

Question 28

Predict the sign of entropy during condensing

Answer 28

Negative

Question 29

Predict the sign of entropy during sublimation

Answer 29

Positive

Question 30

Predict the sign of entropy during vapour deposition

Answer 30

Negative

Question 31

Predict the sign of entropy during freezing

Answer 31

Negative

Question 32

Predict the sign of entropy when dissolving a solute to form a solution

Answer 32

Positive

Question 33

Predict the sign of entropy during precipitation

Answer 33

Negative

Question 34

Predict the sign of entropy during crystallization from a solution

Answer 34

Negative

Question 35

Predict the sign of entropy during a chemical reaction when a solid or liquid react to form a gas

Answer 35

Positive

Question 36

Predict the sign of entropy during a chemical reaction when gases react to form a solid or a liquid

Answer 36

Negative

Question 37

Predict the sign of entropy during a chemical reaction when there is a increase in the number of moles of gas

Answer 37

Positive

Question 38

Predict the sign of entropy during a chemical reaction when there is a decrease in the number of moles of gas

Answer 38

Negative

Question 39

State the value of standard entropy for a perfect crystal of a substance at 0 K

Answer 39

0 J K⁻¹ mol⁻¹

Question 40

Describe a substance that has a standard entropy of 0

Answer 40

A perfect crystal at 0 K

Question 41

In terms of spontaneity, describe a reaction that has a positive ΔG value

Answer 41

Non-spontaneous

Question 42

In terms of spontaneity, describe a reaction that has a negative ΔG value

Answer 42

Spontaneous

Question 43

In terms of spontaneity, describe a reaction that has a positive ΔH value and positive ΔS value

Answer 43

The reaction will be spontaneous at high temperatures

Question 44

In terms of spontaneity, describe a reaction that has a positive ΔH value and negative ΔS value

Answer 44

The reaction will be non-spontaneous at all temperatures

Question 45

In terms of spontaneity, describe a reaction that has a negative ΔH value and positive ΔS value

Answer 45

The reaction will be spontaneous at all temperatures

Question 46

In terms of spontaneity, describe a reaction that has a negative ΔH value and negative ΔS value

Answer 46

The reaction will be spontaneous at low temperatures

Question 47

What is the value for ΔG when calculating the temperature at which a reaction becomes spontaneous?

Answer 47

0 kJ K⁻¹ mol⁻¹

Question 48

When does the value of the reaction quotient equal the value of the equilibrium constant? (Q = K)

Answer 48

ΔGr = 0 OR when the reaction is an equilibrium

Question 49

What does ΔGr = 0 tell you about a chemical reaction?

Answer 49

It is at equilibrium

Question 50

What is the value for ΔGr at equilibrium?

Answer 50

0 kJ K⁻¹ mol⁻¹