Lesson 1-5

Question 1

Change in Entropy: Positive or Negative

Solid sugar is added to water to form a solution.

Answer 1

Positive

Question 2

Change in Entropy: Positive or Negative

Iodine vapor condenses on a cold surface to form crystals.

Answer 2

Negative

Question 3

Change in Entropy: Positive or Negative

Water freezez

Answer 3

Negative

Question 4

Change in Entropy: Positive or Negative

Student breaks a pyrex beaker

Answer 4

Positive

Question 5

Change in Entropy: Positive or Negative

A gas expands

Answer 5

Positive

Question 6

(Entropy) change measures the dispersal of energy: how much energy is spread out in a particular process

Answer 6

True

Question 7

Entropy, S, is a measure of randomness of disorder. The natural tendency of things is to tend toward (lesser) disorder.

Answer 7

Greater

Question 8

Spontaneity is independent of the (speed or rate of a reaction)

Answer 8

True

Question 9

A (spontaneous process) is one that occurs without outside intervention

Answer 9

True

Question 10

Thermodynamics studies how changes in energy, (enthalpy) and temperature affect spontaneity of a process or chemical reaction

Answer 10

Entropy

Question 11

3 factors to predict spontaneity

Answer 11

Energy change, temperature and entropy change

Question 12

Driving force for a spontaneous process

Answer 12

An increase in the entropy of the universe

Question 13

Determination of the degree of disorderliness

Answer 13

A. Number of arrangement of molecules can have in a system
B. Number of types of molecules as well as number of molecules

Question 14

A reaction will never spontaneously move away from equilibrium

Answer 14

And will always move spontaneously towards equilibrium

Question 15

Spontaneity is a process can be determined from

Answer 15

change in entropy and change in free energy of a system

Question 16

Gibbs free energy formula

Answer 16

△G = △H - T△S

Question 17

Study of the rates of chemical reactions

Answer 17

Chemical Kinetics

Question 18

The rate of a chemical reaction is proportional to the number of collisions between reactant molecules.

Answer 18

Collision Theory

Question 19

Energy required for collisions to be sufficiently energetic to break chemical bonds

Answer 19

Activation Energy

Question 20

Collisions that results in a chemical reactions and form a new product.

Answer 20

Effective Collision

Question 21

No product was formed when collision happens.

Answer 21

Ineffective Collision

Question 22

Substances that help speed up the rate of chemical reactions

Answer 22

Catalysts

Question 23

Process of speeding up a reaction by using catalysts

Answer 23

Catalysis

Question 24

Catalysts and reactants are in the same phase

Answer 24

Homogenous Catalysis

Question 25

Catalysts and reactants are in different phases

Answer 25

Heterogeneous Catalysis

Question 26

Proteins that function as catalyst in all living systems

Answer 26

Enzymes

Question 27

Enzyme lowers the activation energy of a reaction

Answer 27

True

Question 28

Energy level that the reactant molecules must overcome before a reaction can occur

Answer 28

Activation energy

Question 29

Entropy phases

Answer 29

Gasses > Liquids > Solids

Question 30

Entropy Change Formula

Answer 30

△S°rxn = ΣS°(products) - Σ°(reactants)

Question 31

Increase in entropy when

Answer 31

Gas is formed from the reactants

Question 32

Decrease in entropy when

Answer 32

Gaseous reactants are converted to solids or liquids

Question 33

Reduction in disorder during

Answer 33

Synthesis reactions

Question 34

Increase in disorder during

Answer 34

Decomposition reactions

Question 35

Reaction that occurs under a given set of condition

Answer 35

Spontaneous reactions

Question 36

Reaction that does not occur under a given set of conditions

Answer 36

Nonspontaneous reactions

Question 37

△H - △S +

Answer 37

Always negative, Spontaneous

Question 38

△H + △S -

Answer 38

Always Positive, Nonspontaneous

Question 39

△H - △S -

Answer 39

Negative at Low T, Spontaneous

Question 40

△H + △S +

Answer 40

Positive at Low T, Nonspontaneous

Question 41

A reaction is at _______ state if the rate of the forward reaction equals the backward reaction

Answer 41

Equilibrium

Question 42

Double arrow

Answer 42

Reversible reaction, at Equilibrium

Question 43

Reaction Quotient mA + nB -> xC + yD

Answer 43

Qc = (C^x)(D^y)/(A^m)(B^n)

Question 44

Conditions that needs to be met for a chemical reaction to occur

Answer 44

Particles in the substance must collide and have enough energy.

Question 45

Why does a candle burn more rapidly when place in an open jar than in air?

Answer 45

Higher oxygen concentration

Question 46

Greater number of reactant are more _____ at higher temperatures

Answer 46

Energetic

Question 47

Second Law of Thermodynamics

Answer 47

For any spontaneous process, the entropy of the universe increases.

Question 48

When hear is added to a pure liquid, the temperature

Answer 48

Increases and the entropy increases

Question 49

Conditions for a reaction to be spontaneous at all temperatures

Answer 49

△H < 0 and △S >=0

Question 50

For a spontaneous reaction

Answer 50

△G = △H - T△S must be negative

Question 51

△S = Products - Reactants

Answer 51

True

Question 52

Entropy Change Formula

Answer 52

△Ssys = (Mass)(Molar Mass)(△Fusion: Negative)(1000j/Kj)/(°C+273.15)

Question 53

Hg Mercury 113 g

Answer 53

-5.51 J/K

Question 54

Cu Copper 125 g

Answer 54

-19.1 J/K

Question 55

Au Gold 97 g

Answer 55

-4.86 J/K

Question 56

Hg Mercury 89 g

Answer 56

-4.34 J/K

Question 57

Au Gold 69 g

Answer 57

-3.47 J/K

Question 58

Hg Mercury 67 g

Answer 58

-3.26 J/K

Question 59

Cu Copper 69 g

Answer 59

-10.6 J/K

Question 60

First Law of Thermodynamics

Answer 60

Energy cannot be created or destroyed. Total energy of the universe is constant. Energy can only be converted.

Question 61

When heat is added to a system, the amount of heat added can

Answer 61

increase the temperature, increase internal energy, and do external work.

Question 62

The lowest possible temperature is absolute zero, at

Answer 62

0 on the Kelvin scale and -273 degrees on the Celsius scale.

Question 63

When you breathe on your hand, the temperature of the exhaled air reaching your hand

Answer 63

Depends on how you blow

Question 64

The second law of thermodynamics tells us that heat cannot flow from

Answer 64

cold to hot without external energy.

Question 65

Heat engines such as jet engines are more efficient when run at

Answer 65

High temperatures