Core Organic Chemistry

Question 1

What is meant by a “hydrocarbon”

Answer 1

A compound made up of only hydrogen and carbon atoms

Question 2

Some hydrocarbons are unsaturated, what does this mean

Answer 2

They contain double covalent bonds

Question 3

Alkanes are a homologous series, what does this mean

Answer 3

A series of compounds in the same functional group whose successive reactions differ by CH

Question 4

What is the general formula for an alkane

Answer 4

CnH2n+2

Question 5

Give the structural formula of butane

Answer 5

C4H10

Question 6

What is determined by the functional group of an organic molecule

Answer 6

The characteristics of their reactions

Question 7

What is meant by the term aliphatic

Answer 7

A chain of carbons that are open (not rings)

Question 8

Benzene is a special type of ring structure, what can it be described as

Answer 8

A six carbon ring with a pie cloud

Question 9

Alkanes are saturated carbons, so contain only _______
carbon-carbon and
_______-hydrogen bonds

Answer 9

Single. Carbon.

Question 10

What is a carbon chain that contains at least one double covalent bond between carbons

Answer 10

Alkene

Question 11

Name the following compounds

A) C6H14
B) C3H8
C) C9H20

Answer 11

A) hexane
B) propane
C) nonane

Question 12

How many carbon atoms make up the following alkanes

A) Butane
B) Methane
C) Octane

Answer 12

A) 4
B) 1
C) 8

Question 13

What is the name given to a saturated cyclic 6 carbon ring

Answer 13

Cyclohexane

Question 14

An organic compound has the formula CH3CHO identify its functional group

Answer 14

Aldehyde

Question 15

What is the functional group of in an alcohol

Answer 15

R-O-H

Question 16

What is meant by the empirical formula

Answer 16

The ratio of elements in a compound but not the actual number or arrangement

Question 17

Give the general formula for alkenes

Answer 17

CnH2n

Question 18

Give the molecular formula for an alkene with 15 carbons

Answer 18

C15H30

Question 19

Draw the skeletal formula of ethanal

Answer 19

/\/OH

Question 20

Give the structural formula for heptane

Answer 20

C7H16

Question 21

What is the name given to isomers with the same molecular formula but a different structure

Answer 21

Structural isomers

Question 22

What is homolytic fission

Answer 22

Chemical bond dissociation of a molecule where each of the fragments retain one of the originally bonded electrons

Question 23

What is produced in heterolytic fission

Answer 23

Carbanions (+ve)

Carbocations (-ve)

Question 24

Curly arrows are used in reaction mechanisms to show _________

Answer 24

Flow of electrons

Question 25

Alkenes generally undergo what type of reaction

Answer 25

Addition reactions

Question 26

In some reactions, a functional group is replaced by a different group, what is this type of mechanism

Answer 26

Substitution reaction

Question 27

When a small molecule is removed from a compound and leaves behind an alkene, what is the type of reaction known as

Answer 27

Elimination reaction

Question 28

What is the general formula for the alkanes

Answer 28

CnH2n+2

Question 29

Every carbon in an alliance has four single, covalent bonds, what type of bond are these single covalent bonds

Answer 29

Sigma bonds

Question 30

What is the approximate bond angle around each carbon atom in an alkane

Answer 30

109.5^o

Question 31

Why does the boiling point of the alkanes increase with increasing chain length

Answer 31

Longer chains means greater surface area resulting in stronger London forces between molecules, more energy is then needed to seperate molecules

Question 32

As alkenes become branched, what happens to the boiling points and why

Answer 32

The boiling points decrease because the surface area with the London forces acting between chains decreases

Question 33

Write a balanced equation for the complete combustion of pentane

Answer 33

C5H12+8O2—>5CO2+6H2O

Question 34

What products are formed during incomplete combustion

Answer 34

CO and H2O

Question 35

Poorly maintained household boilers can leak products of incomplete combustion, why does this pose a health hazard

Answer 35

The production of CO is dangerous as carbon monoxide is poisonous

Question 36

Alkanes can react with halogens such as chlorine to grrat a chloro-alkane, name the mechanism for the type of reaction

Answer 36

Radical Substitution

Question 37

Name the three stages that take place in radical substitution

Answer 37

1) initiation 2) propagation 3) termination

Question 38

Using Cl2 as a starting material, describe the conditions required for the initial stage of the free radical substitution reaction

Answer 38

The bond in Cl-Cl is broken by homolytic fission and the electrons are shared between the atoms

Question 39

Give two equations to show the main stage of the reaction using ethane as the organic molecule

Answer 39

C2H6 Cl• —> CH5• + HCl | CH5• + Cl2 —> CH5Cl + Cl•

Question 40

The final stages of the reaction involve radicals reacting with radicals, write three equations to show this happening for the reaction between Chlorine and Ethane

Answer 40

Cl• + Cl• —> Cl2 | Cl• + CH5• —> CH