Chapter 12 - Alkanes

Question 1

What is the average bond enthalpy?

Answer 1

Is a measurement of covalent bond strength

Question 2

What is an aliphatic hydrocarbon?

Answer 2

Hydrocarbon with carbon atoms joined together in a straight line or branched chain.

Question 3

What is an alicyclic hydrocarbon?

Answer 3

Hydrocarbons arranged in non aromatic rings with or without side chains

Question 4

What is an aromatic hydrocarbon?

Answer 4

Hydrocarbon that contains at least one benzene ring

Question 5

What is the general formula for alkanes?

Answer 5

CnH2n+2

Question 6

What is the general formula for alkenes?

Answer 6

CnH2n

Question 7

What is the general formula for alcohols?

Answer 7

CnH2n+1OH

Question 8

What is a structural isomerism?

Answer 8

When molecules have the same molecular formula but different structural formula

Question 9

What are stereoisomers?

Answer 9

Organic compounds with the same molecular formula but different arrangement of atoms in space

Question 10

What is E/Z isomerism?

Answer 10

Is caused by limited rotation about C=C double bonds

Question 11

What is Cis/Trans isomerism?

Answer 11

Special type of E/Z isomerism where the two substituents on each carbon atom are the same

Question 12

What is homolytic fission?

Answer 12

It happens when each boning atom receives one electron from the bonded pair forming two radicals

Question 13

What is heterolytic fission?

Answer 13

When one bonding atom receives both electrons from bonded pair

Question 14

What are radical?

Answer 14

Highly reactive, neutral species

Question 15

How is a covalent bond formed from two radicals?

Answer 15

The radicals collide and the electrons are involved in the bond formation

Question 16

Are alkanes bonds polar or non-polar?

Answer 16

Non-polar

Question 17

Why are alkane bonds non-polar?

Answer 17

Carbon and hydrogen have similar electronegatives

Question 18

What is the shape of an alkane?

Answer 18

Tetrahedral

Question 19

What is the angle of an alkane?

Answer 19

109.5

Question 20

What type of intermolecular forces do alkanes have?

Answer 20

London forces

Question 21

Why do alkanes have London forces?

Answer 21

Induced dipole-dipole interaction, because the bond are non-polar

Question 22

Why does the boiling point increase as chain length increases?

Answer 22

More surface area so more induced dipole dipole interactions = more energy required to overcome attraction

Question 23

Why are alkanes insoluble?

Answer 23

Hydrogen bonds in water are stronger than alkanes london forces of attraction

Question 24

What is complete combustion?

Answer 24

Combustion that occurs with plentiful supply of air

Question 25

What is incomplete combustion?

Answer 25

Combustion in a limited supply of oxygen

Question 26

What are the products of incomplete combustion?

Answer 26

• Water
• Carbon dioxide
• Carbon monoxide

Question 27

How are halogenoalkanes formed from from alkanes?

Answer 27

Radical Substitution

Question 28

What does alkanes need to reactive with halogens?

Answer 28

UV light

Question 29

What are the three stages of free radical substitution?

Answer 29

• Initiation
• Propagation
• Termination