Chapter 5-Thermochemistry,Free Energy

Question 1

The energy of the reactants is greater than the energy of the products

Answer 1

Exergonic reaction

Spontaneous -negative

Question 2

The energy of the reactants is less than the energy of the products

Answer 2

Endergonic energy

Non-spontaneous-positive

Question 3

The difference in the heat contents of the products and the reactants is called

Answer 3

heat of a reaction

Question 4

For an exothermic reaction in which no work is done on or by the reaction, the internal energy must

Answer 4

decrease

Question 5

Entropy is a statistical measure of

Answer 5

disorder of a system

Question 6

If a chemical reaction is spontaneous, the total entropy of the chemical system and its surroundings

Answer 6

always increases

Question 7

The thermodynamic quantity that combines enthalpy and entropy is

Answer 7

free energy

Question 8

Oxidation and reduction occur

Answer 8

simultaneously

Question 9

The key characteristic of redox reactions is the

Answer 9

passing of one or more electrons from one species to another

Question 10

__________ are assigned to each element as a formalism to keep track of the movement of electrons between species.

Answer 10

Oxidation numbers

Question 11

Simply stated, the gain of electrons is

Answer 11

reduction

Question 12

During oxidation, the oxidation number of a species becomes

Answer 12

more positive

Question 13

The species that is being reduced will have

Answer 13

a more negative oxidation state after the reduction has occurred.

Question 14

The goal of a redox reaction is to keep the number of electrons lost

Answer 14

equal to the number of electrons gained

Question 15

Changes in the __________ can also be used to balance redox equations.

Answer 15

oxidation numbers

Question 16

When a neutral atom loses an electron, the ion which is formed has

Answer 16

a negative charge

Question 17

The oxidation number of any free element is

Answer 17

zero

Question 18

The oxidation number of sulfur in H 2SO 4 is

Answer 18

+6

Question 19

The oxidation number of any alkali metal ion is

Answer 19

+1

Question 20

The oxidation number of oxygen in the compound CaO is

Answer 20

-2

Question 21

When assigning oxidation numbers to elements in a compound, the sum of all the charges must equal

Answer 21

zero

Question 22

When assigning oxidation numbers to elements in covalent compounds, the __________ will have the negative oxidation number.

Answer 22

more electronegative element

Question 23

Exothermic Reaction

Answer 23

Gives off heat

Question 24

Endothermic Reaction

Answer 24

Requires Heat

Question 25

Activation Energy

Answer 25

Initial energy required for a reaction to occur

Question 26

Kinetics (rate of reaction)

Answer 26

1.Concentration
2.Temperature- increases rate by increasing kinetic energy of reactants
3. Catalysts- lowers activation energy, rate increases. Speeds up chemical reaction, remains unchanged at completion.

Question 27

Markovnikov’s rule

Answer 27

the hydrogen will bond to the carbon in the double bond with more hydrogens bonded directly to the alkene.

Question 28

Condensation & hydrolysis

Answer 28

• occur in opposite directions.

Question 29

Condensation -

Answer 29

joins molecules and often produces water (dehydration synthesis)

Question 30

Hydrolysis -

Answer 30

breaks molecules, and water is a reactant (decomposition)

Question 31

Oxidation & reduction (redox) - occur

Answer 31

simultaneously

Question 32

Oxidation -

Answer 32

loss of electrons, may involve addition of oxygen,
or removal of hydrogen.

Question 33

Reduction -

Answer 33

gain of electrons, may add hydrogen or remove oxygen. (Ex: Combustion - reaction with oxygen)