Chapters 13-18

Question 1

What is it about oxygen that defies explanation using just VSEPR and hybridization theory?

Answer 1

The fact that oxygen is paramagnetic.

Question 2

What makes materials paramagnetic?

Answer 2

unpaired electrons in their electron clouds.

Question 3

What are Michael Faraday’s dates?

Answer 3

1791-1867.

Question 4

Who first discovered that oxygen is attracted to magnetic fields? When?

Answer 4

Michael Faraday in 1847.

Question 5

Who solved the mystery of oxygen’s paramagnetism?

Answer 5

Friedrich Hund and Robert Mulliken in 1933. An electron in a molecule could move through larger regions defined by combinations of overlapping atomic orbitals.

Question 6

Define a chemical reaction.

Answer 6

Any process that results in the breaking, formation, or rearrangement of chemical bonds.

Question 7

Are processes like melting ice or boiling water chemical reactions?

Answer 7

No. Just physical changes. The chemical bonds remain the same.

Question 8

Is radioactive decay a chemical reaction?

Answer 8

No– the element’s identity is changed because of nuclear changes, not changes in the chemical bonds.

Question 9

What are 4 basic types of chemical reactions?

Answer 9

Synthesis, Decomposition, Single Displacement and Double Displacement.

Question 10

What is a synthesis chemical reaction?

Answer 10

when 2 or more smaller reagents combine to form a single larger product.

Question 11

What is a Decomposition chemical reaction?

Answer 11

a process in which larger starting materials are broken down into smaller and more numerous products.

Question 12

What is a Single Displacement chemical reaction?

Answer 12

combination of synthesis and decomposition, in which one reactant replaces a part of another molecule, liberating that which it replaced.

Question 13

What is a Double Displacement chemical reaction?

Answer 13

also called metathesis, 2 or more reactants exchange a portion of themselves with one another.

Question 14

Define Stoichiometry

Answer 14

The molar ratios of each reactant and product involved in a given chemical reaction.

Question 15

When balancing chemical equations, which species should you leave to the last step?

Answer 15

The pure elements.

Question 16

What is a limiting reagent?

Answer 16

The reagent we expect to be depleted first in a chemical reaction.

Question 17

What are James Prescott Joule’s dates?

Answer 17

1818-1889.

Question 18

What was James Joule’s profession?

Answer 18

He owned a brewery.

Question 19

What 2 things do engines produce?

Answer 19

Heat and work.

Question 20

What did Joule notice about the relationship between heat and work?

Answer 20

He noticed that the more heat a device produced, the less work it could do per unit of fuel consumed. Minimizing heat meant maximizing work.

Question 21

What is the definition of a Joule?

Answer 21

It is the amount of kinetic energy imparted to an object when 1 newton of force acts on it over a 1-meter distance.

Question 22

What is the definition of a calorie?

Answer 22

Equal to 4.17 joules, it is the amount of energy needed to heat 1 gram of water 1 degree centigrade.

Question 23

What is the definition of the British Thermal Unit (BTU)?

Answer 23

The amount of heat needed to raise the temperature of 1 pound of water by 1-degree Fahrenheit.

Question 24

What is the first law of thermodynamics?

Answer 24

Energy cannot be created or destroyed. It can only be exchanged.

Question 25

What is the definition of enthalpy?

Answer 25

When heat is equal to energy in a system performing no work, that heat is given the name enthalpy.

Question 26

What is an exothermic reaction?

Answer 26

One which releases heat to its surroundings.

Question 27

What is an endothermic reaction?

Answer 27

One which absorbs heat from its surroundings.

Question 28

What is the Specific Heat of a substance?

Answer 28

A measure of how much energy is required to heat 1 gram of material by 1-degree centigrade. Denoted by S or c.

Question 29

What is the specific heat of water?

Answer 29

4.18 joules per degree centigrade.

Question 30

How do we measure the heat capacity of a sample?

Answer 30

multiply the specific heat by the mass of the material.

Question 31

What are Pierre-Eugene-Marcellin Berthelot’s dates?

Answer 31

1827-1907.

Question 32

What did Berthelot invent?

Answer 32

The bomb calorimeter.

Question 33

What are Germain Hess’s dates?

Answer 33

1802-1850

Question 34

What is a state function?

Answer 34

properties that are identical for all systems of a particular kind no matter what happened to a system previously.

Question 35

What is Hess’s law?

Answer 35

The enthalpy change for a complex process is equal to the sum of the enthalpy changes of the smaller steps making it up, no matter what those smaller steps might be.

Question 36

When did Hess formulate his law?

Answer 36

1840

Question 37

The higher the enthalpy, the _____ the bond will be.

Answer 37

Stronger

Question 38

What’s the bond enthalpy for a carbon-carbon bond?

Answer 38

348 Kj/mol

Question 39

What are Ludwig Boltzmann’s dates?

Answer 39

1844-1906.

Question 40

What was a microstate for Boltzmann?

Answer 40

a state that considered the position and motion of every atom in a system.

Question 41

What is Boltzmann’s equation?

Answer 41

Relates the randomness of a chemical system to the number of microstates accessible to that system: S = Kb*lnW

Question 42

What is the second law of thermodynamics?

Answer 42

entropy, or randomness, in a closed system tends to increase unless it is countered by the input of energy from an outside source.

Question 43

What does Boltzmann’s equation and the second law of thermodynamics say about the fate of the universe?

Answer 43

that the overall randomness of matter in the universe will constantly increase until it simply can’t any more.