Alkanes

Question 1

What types of bonds does carbon form in compounds?

Answer 1

Covalent

Question 2

How many bonds does carbon always form?

Answer 2

4 covalent bonds

Question 3

Molecular formula

Answer 3

The number of atoms of each type of element in a molecule

Question 4

Empirical formula

Answer 4

The simplest ratio of atoms of each type of element in a compound

Question 5

Structural formula

Answer 5

This shows the arrangement of atoms in the molecule

Question 6

Displayed formula

Answer 6

This shows all the bonds between the atoms in a molecule

Question 7

Skeletal formula

Answer 7

This shows the shape of the carbon skeleton

Question 8

Structural isomers

Answer 8

Compounds which have the same molecular formula but different structural formula

Question 9

Functional group

Answer 9

A group of atoms responsible for the characteristic reactions of a compound

Question 10

Alcohol functional group

Answer 10

OH

Question 11

Carboxylic acid functional group

Answer 11

COOH

Question 12

Amine functional group

Answer 12

NH2

Question 13

Alkene functional group

Answer 13

C=C

Question 14

Chloro functional group

Answer 14

Cl

Question 15

Aldehyde functional group

Answer 15

CHO

Question 16

Homologous series

Answer 16

A family of compounds containing the same functional group and the same general formula but with each successive member has an extra CH2

Question 17

Hydrocarbons

Answer 17

Compounds containing carbon and hydrogen only

Question 18

Saturated hydrocarbon

Answer 18

Only contains C-C single bonds

Question 19

Unsaturated hydrocarbon

Answer 19

Contains a C-C multiple bond

Question 20

Aliphatic hydrocarbon

Answer 20

Branched, unbranched or non aromatic ring

Question 21

Alicyclic hydrocarbon

Answer 21

Non aromatic ring

Question 22

Aromatic hydrocarbon

Answer 22

Contains one or more benzene rings

Question 23

The general formula of an aliphatic alkane

Answer 23

CnH2n+1

Question 24

What is the structure of an aliphatic alkane?

Answer 24

They can have branched or unbranched chains

Question 25

What type of hydrocarbon are alkanes?

Answer 25

Saturated

Question 26

What types of bonds are the C-C and C-H bonds in alkanes?

Answer 26

Sigma bonds

Question 27

Sigma bonds

Answer 27

The overlap of orbitals between bonding atoms

Question 28

What is the bond angle and bond shape in alkanes?

Answer 28

109.5 and tetrahedral

Question 29

Why do alkanes not react with most common reagents?

Answer 29

Because they have high bond enthalpies due to strong bonds and they have a low polarity of the sigma bonds due to carbon and hydrogen having similar electronegativities

Question 30

Which alkanes will show structural isomerism?

Answer 30

Those with 4 or more carbons

Question 31

The general formula of a cyclic alkane?

Answer 31

CnH2n

Question 32

What two factors does the boiling points of alkanes depend on?

Answer 32

Chain length and chain branching

Question 33

What is the trend in boiling points with chain length in alkanes?

Answer 33

As the number of carbons increase, the boiling points will increase

Question 34

Explain the trend in boiling points with chain length in alkanes?

Answer 34

As the number of carbons increase there is more points of contact so there are more London forces present so more energy is needed to overcome the forces

Question 35

What is the trend in boiling points with chain branching in alkanes?

Answer 35

Branched chain alkanes have lower boiling points than their unbranched isomers

Question 36

Explain the trend in boiling points with chain branching in alkanes?

Answer 36

As the branching increases there is less points of contact so there is less London forces present so less energy is needed to overcome the forces

Question 37

Complete combustion

Answer 37

In a plentiful supply of oxygen, carbon dioxide and water are produced

Question 38

Incomplete combustion

Answer 38

When insufficient oxygen is present, carbon monoxide and water are produced and can also result in the formation of carbon and water

Question 39

Halogenation

Answer 39

When alkanes react with halogens such as chlorine and bromine

Question 40

What are the conditions of halogenation?

Answer 40

UV light

Question 41

What is the type of mechanism in halogenation?

Answer 41

Radical substitution

Question 42

What is the type of bond breaking in halogenation?

Answer 42

Homolytic fission

Question 43

Homolytic fission

Answer 43

The breaking of a covalent bond to form 2 radicals

Question 44

What are the products of halogenation?

Answer 44

Haloalkane + either HCl or HBr

Question 45

Initiation step of halogenation

Answer 45

Chlorine radicals are produced because UV light has sufficient energy to break the Cl-Cl bond

Question 46

Radicals

Answer 46

Species that contain unpaired electrons

Question 47

Propagation step of halogenation

Answer 47

A radical reacts with a molecule, and a new radical and molecule are produced, leading to a chain reaction

Question 48

Termination step of halogenation

Answer 48

Two radicals combine and the reaction sequence stops

Question 49

What are two limitations of halogenation reactions?

Answer 49

Further substitution and substitution on different carbons