Topic 9- Introduction to Organic Chemistry

Question 1

What sort of bonds do carbon atoms form?

What three types of carbon-carbon bonds?

What are the three ways that carbon atoms can be arranged in?

What is the chemistry of an organic compound determined by?

What is the molecular formula?

What is the empirical formula?

What is the structural formula?

What is the displayed formula?

What is the skeletal formula?

What aren’t shown as symbols in the skeletal formula?

Answer 1

Strong covalent bonds to each other

Single, double or triple

• Straight chains
• Branched chains
• Rings

Its functional group

The exact number of atoms of each element present in the molecule

The simplest whole number ratio of atoms of each element in the molecule

The minimal detail using conventional groups, for an unambiguous structure

Shows both the relative placing of atoms and the number of bonds between them

Used to show a simplified organic formula by removing hydrogen atoms from alkyl chains leaving just a carbon skeleton and associated functional groups

The carbon atoms and the hydrogen’s attached to them aren’t shown as symbols.

Question 2

What is the general formula?

What is a root?

What are the roots for the following number of carbons:

1

2

3

4

5

6

What are prefixes?

What are the side chains for the following prefixes:

Methyl

Ethyl

Propyl

Butyl

Pentyl

Hexyl

Answer 2

Represents any member of a homologous series

A systematic name has a root that tells us the longest unbranched hydrocarbon chain or ring

Meth-

Eth-

Prop-

But-

Pen-

Hex-

Added at the beginning of the root, for example, side chains whose names tells us the number of carbons

CH3-

C2H5-

C3H7-

C4H9-

C5H11-

C6H13-.

Question 3

What are suffixes?

Give an example of a suffix?

What can functional groups consist of?

What does each functional group have (full detail)?

What is a homologous series?

What do all homologous series share the same?

What does the formula of a homologous differ from its neighbour by?

What do all members of homologous series contain?

What do all members of homologous series have that’s similar?

What gradual change is shown in a homologous series?

Answer 3

Added at the end of the root

For example, alcohols have the suffix -ol, as in ethanol (CH3 CH2 OH)

One atom, a group of atoms or multiple bonds between carbon atoms

Each functional group has its own distinctive properties which means that the properties of a compound are governed by the functional group (s) in it

A series of compounds of similar structure in which each member differs from the next by a common repeating unit, CH2

All share the same general formula

Formula of a homologue differs from its neighbour by CH2 (eg CH4, C2H6 etc)

Contain the same functional group

Have similar chemical properties

Show a gradual change in physical properties as molar mass increases.

Question 4

What does a suffix show in a systematic name?

What are the two steps for a systemic name?

What are the suffixes for the following functional groups:

Alkane

Alkene

Alkyne

Alcohol

Aldehyde

Ketone

Acid

Why must be given in many cases to avoid ambiguity?

What are substituents?

What must be numbered in substituents?

Answer 4

An ending that tells you which functional group is present

• See if any functional groups are present
• Add relevant ending to the basic stem
• ANE
• ENE
• YNE
• OL
• AL
• ONE
• OIC ACID

In many cases the position of the functional group must be given to avoid any ambiguity

Many compounds have substituents (additional atoms, or groups) attached to the chain

Their position is numbered.

Question 5

How are carbon based substituents named?

What is their prefixes and give an example?

How do you number the principle chain?

How do side chain names appear and give some examples?

What is each side chain given?

What happens if identical side chains appear more than once (full detail with examples)?

How are numbers separated from names by and give an example?

How are numbers separated from numbers by and give an example?

Answer 5

Carbon based substituents are named before the chain name

They have the prefix -yl added to the basic stem (eg CH3 is methyl)

Number the principle chain from one end to give the lowest numbers

Side chain names appear in alphabetical order (butyl, ethyl, methyl, propyl)

Each side chain is given its own number

If identical side chains appear more than once, prefix with di, tri, tetra, penta, hexa)

Numbers are separated from names by a hyphen (eg 2-methylheptane)

Numbers are separated from numbers by a comma (eg 2,3 - dimethylbutane).

Question 6

What is not always the longest chain in alkenes?

What must alkenes contain?

What does the name of an alkene end in?

What is the position of an alkene counted from?

What is the position of an alkene indicated by?

What is the side chain of an alkene similar to?

What is the side chain position of an alkene based on?

Answer 6

In alkenes, the principle chain is not always the longest chain

Must contain the double bond

-ENE

Count from one end as with alkanes

Indicated by the lower numbered carbon atom on one end of the C=C bond

Side chain of an alkene similar to alkanes

Position is based on the number allocated to the double bond.

Question 7

What is the definition of structural isomerism?

What are the four properties of chain structural isomerism?

What are the five properties of position structural isomerism?

What are the three properties of functional group structural isomerism?

What can sometimes occur in the same molecule?

What does it mean the more carbon atoms there are?

In nomenclature, which way do you count from?

What does the double bond do in nomenclature?

What does anything mean in the bracket mean?

Where can you never have a methyl group attached in a chain?

Answer 7

Compounds that have the same molecular formula but different structural formula

• Different arrangements of the carbon skeleton
• Similar chemical properties (same)
• Slightly different physical properties
• More branching= lower boiling point
• Same carbon skeleton
• Same functional group
• Functional group is in a different position
• Same chemical properties- slightly different physical properties
• Different functional group
• Different chemical properties
• Different physical properties

Sometimes more than one type of isomerism occurs in the same molecule

The greater the number of possible isomers

Left/right to count from depending on which side has the lowest number for the side chains

The double bond takes the lowest number

Anything in the bracket means attached to the carbon (not always just the side chains)

You can never have a methyl group attached to the first carbon in the chain.