Organic AS

Question 1

What is the empirical formula

Answer 1

Empirical formula shows the simplest whole number ratio of elements within a molecule.

Question 2

What is the molecular formula

Answer 2

Molecular formula shows the actual number of atoms of each element in a molecule

Question 3

What does the structural formula show

Answer 3

Structural formula shows how the atoms are arranged in a molecule

Question 4

What does the displayed formula show

Answer 4

Displayed formula shows a drawing of the arrangement of atoms in a molecule
ALL bonds must be shown

Question 5

What does the skeletal formula show

Answer 5

Skeletal formula shows the carbon backbone and functional groups within molecules, no carbon-hydrogen bonds are shown

Question 6

What are alkanes

Answer 6

Alkanes have single bonds between each carbon atom, all other available bonds are made to hydrogen atoms – they are called ‘saturated’ hydrocarbons

Question 7

What are alkenes

Answer 7

Alkenes have a double bond between two of their carbon atoms – they are called ‘unsaturated’ hydrocarbons

Question 8

What are alkly groups

Answer 8

Alkly groups are carbon chain groups bonded to another carbon chain
- CH3- methyl

• CH2CH3- ethyl

СН2СН2СН3-propyl

-СН2СН2СН2СН3-butyl
follows the same prefix as usual.

Question 9

Ant does the functional group do

Answer 9

The functional group of a molecule dictates its chemistry, and its presence enables us to predict how the molecule is likely to react

Question 10

What are structural isomers

Answer 10

Molecules that have the same molecular formula but different structures are called structural isomers.

Question 11

What differs between chain isomers

Answer 11

They have different carbon chain arrangements to one another

Question 12

What is Positional Isomerism

Answer 12

Where molecules that have the same molecular formula but have their functional group in different places

Question 13

What are the steps to naming organic molecules

Answer 13

1. When naming a compound, the length of the longest carbon chain must be determined. Use the prefix as for an alkane (meth, eth, prop…etc.).
2. Alkyl and functional groups must be identified. Use the appropriate suffix (or prefix for halogenoalkanes) (-ol, -al, -oic acid, -yl for alkyl groups.).
3. If a positional isomer is possible, the carbons in the chain must be numbered. The chain is always numbered, so a functional group or alkyl group is bonded to the lowest carbon number possible.
4. When molecules contain two or more functional or alkyl groups, they are placed in alphabetical order