3.1 - Introduction to Organic Chemistry

Question 1

What is the definition of a molecular formula?

Answer 1

A molecular formula gives the actual number of atoms of each element in a molecule

Question 2

What is the definition of a structural formula?

Answer 2

A structural formula shows the atoms carbon by carbon, with the attached hydrogens and functional groups

Question 3

What is the definition of a displayed formula?

Answer 3

A displayed formula shows how all of the atoms are arranged, and all the bonds between them

Question 4

What is the definition of an empirical formula?

Answer 4

An empirical formula gives the simplest whole-number ratio of atoms of each element in a compound

Question 5

What is a homologous series?

Answer 5

A homologous series is a family of compounds that have the same functional group and the same general formula

Question 6

What is the definition of a skeletal formula?

Answer 6

A skeletal formula shows the bonds of the carbon skeleton only, with any functional groups

Question 7

What is the general formula for an alkane?

Answer 7

CnH2n+2

Question 8

What suffix do alkanes have?

Answer 8

Alkanes end in -ane

Question 9

How many other atoms are each carbon atom bonded to in alkanes?

Answer 9

Each carbon is bonded to four other atoms and is therefore saturated

Question 10

What is a halogenoalkane?

Answer 10

A halogenoalkane have a similar structure to alkanes, except at least one of the hydrogen atoms are replaced with a halogen atom

Question 11

What is a cycloalkane?

Answer 11

Cycloalkanes have a ring of carbon atoms with two hydrogens attached to each carbon

Question 12

What is the general formula for a cycloalkane?

Answer 12

They have a general formula of CnH2n

Question 13

Are cycloalkanes saturated?

Answer 13

Cycloalkanes are saturated

Question 14

What is the prefix and suffix for cycloalkanes?

Answer 14

The prefix is cyclo- and the suffix is -ane

Question 15

What is a branched alkane?

Answer 15

A branched alkane is an alkane that doesn’t have all the carbon atoms in one straight chain. They will have the main chain of carbon atoms (whichever is the longest) and one or more carbons coming off the main chain

Question 16

What is an alkene?

Answer 16

An alkene is a hydrocarbon with a carbon-carbon double bond. This double bond means they are unsaturated

Question 17

What is an alcohol?

Answer 17

An alcohol contains the hydroxyl (-OH) functional group

Question 18

What is the general formula for alcohols?

Answer 18

The general formula is CnH2n+1OH

Question 19

What is an aldehyde?

Answer 19

An aldehyde has a -CHO group on the end of a carbon chain, with a double bond between the carbon and the oxygen

Question 20

What is the suffix for an aldehyde?

Answer 20

Aldehydes end in -al

Question 21

What is a ketone?

Answer 21

Ketones contain a carbon-oxygen double bond, except it isn’t on the end of the main carbon chain

Question 22

What is the suffix for a ketone?

Answer 22

The suffix for a ketone is -one

Question 23

What is a carboxylic acid?

Answer 23

Carboxylic acid all contain the carboxyl functional group; this is a COOH with one carbon-oxygen bond being a double bond and the other being a single bond

Question 24

What is the suffix for a carboxylic acid?

Answer 24

The suffix is -oic acid

Question 25

How are straight-chain alkanes named?

Answer 25

To name a straight-chain alkane, find out the number of carbon atoms and add -ane to the end

Question 26

How are branched alkanes named?

Answer 26

First of all, find the longest carbon chain. The side chains are then worked out and how many carbon atoms are attached to the main chain. The different carbon chains are named in alphabetical order

Question 27

What happens if there are two or more of the same type of side chain?

Answer 27

Add di- for two, add tri- for three etc…

Question 28

How are cycloalkanes named?

Answer 28

Cycloalkanes have the same as their straight-chain equivalent, but with cyclo- attached to the front. If the cycloalkane has an alkyl group attached, the number is not needed, only the name. If there is more than one alkyl group, the numbers should be as low as possible

Question 29

What is the order of priority out of the following? Other Functional Groups, Halogens, Alkenes and Alkyl Groups

Answer 29

Halogens, alkyl groups, alkenes and then other functional groups

Question 30

What is a mechanism?

Answer 30

A mechanism breaks down a reaction into a series of stages

Question 31

What does a curly, double-headed arrow show?

Answer 31

It shows the movement of two electrons

Question 32

What is a structural isomer?

Answer 32

A structural isomer has the same molecular formula, but a different structural formula (i.e. the atoms are connected in different ways)

Question 33

What are the three types of structural isomers?

Answer 33

Chain isomers, position isomers and functional group isomers

Question 34

What is a chain isomer?

Answer 34

A chain isomer has the same functional group but a different arrangement of the carbon skeleton

Question 35

What is a position isomer?

Answer 35

Position isomers have the same carbon skeleton and the same atoms or groups of atoms attached. The difference is that the atoms or groups of atoms are attached to different carbon atoms

Question 36

What is a functional group isomer?

Answer 36

Functional group isomers have the same atoms arranged in different functional groups

Question 37

What is a stereoisomer?

Answer 37

Stereoisomers have the same structural formula but their atoms are arranged differently in space. E/Z isomerism is an example

Question 38

Why are carbon double bonds different to carbon single bonds?

Answer 38

Carbon-carbon double bonds are planar and atoms can’t rotate around them. This restricted rotation causes E/Z isomerism

Question 39

What is an E isomer?

Answer 39

An E isomer is one that has matching groups on the opposite side of the carbon-carbon double bond

Question 40

What is a Z isomer?

Answer 40

A Z isomer is one that has matching groups both above or both below a double bond

Question 41

Why are Cahn-Ingold-Prelog rules used?

Answer 41

They are used to work out the E and Z isomers of a molecule with three or four different groups attached

Question 42

How are Cahn-Ingold-Prelog rules used?

Answer 42

The different atoms attached to either side of the double bond are each given their atomic number and are ranked in importance with the highest atomic number being the most important