C11- Organic Chemistry

Question 1

What is a hydrocarbon?

Answer 1

A hydrocarbon contains carbon and hydrogen only. They can be saturated or unsaturated:

Saturated = single bonds only.
Unsaturated= carbon-carbon multiple bonds.

Question 2

What is a homologous series?

Answer 2

A family of compounds with similar chemical properties, and the same functional group.
Simplest homologous series= alkanes

Question 3

What is a functional group?

Answer 3

The part of the organic molecule which is responsible for its chemical properties.

Question 4

What can hydrocarbons be classified as?

Answer 4

Aliphatic- carbon atoms joined in straight or branched chains or non-aromatic rings.

Alicyclic- carbon atoms joined in ring (cyclic) structures.(branched or non branched)

Aromatic- some or all carbons are found in a benzene ring.

Question 5

What are the 3 homologous series of aliphatic hydrocarbons?

Answer 5

Alkanes- single C-C bonds.
Alkenes- atleast one C=C (double bond)
Alkynes- atleast one triple carbon to carbon bond.

Question 6

Naming aliphatic alkanes

Answer 6

1. All alkanes have suffix -ane.
2. Identify longest continuous chain of carbon atoms.
3. Identify side chains (alkyl groups). The name of the alkyl group is added as a prefix.
4. Add numbers before any alkyl group to show their position on the chain.

Question 7

Naming alicyclic alkanes.

Answer 7

1. Same process as naming aliphatic alkanes.

2. Add the prefix cyclo-

Question 8

Naming alkenes

Answer 8

1. Suffix = -ene
2. Identify longest continuous carbon chain.
3. Position of double bond must be stated for alkenes that have 4+ carbon atoms in the longest chain.

Question 9

Naming compounds containing functional groups.

Answer 9

1. identify longest unbranched chain of carbon atoms. (Stem= name of corresponding alkane)
2. identify functional groups/ alkyl side chains.
3. number side chains/functional group to show their positions on longest unbranched chain.

Question 10

Naming alcohols.

Answer 10

1. -OH functional group.
2. Identify longest carbon chain.
3. Identify which carbon atom the functional group is on.
4. Combine suffix and stem.

Question 11

What is meant by molecular and empirical formula?

Answer 11

Molecular formula- shows the number and type of atoms of each element present in a molecule.
(Does not show how atoms are joined together)

Empirical formula- simplest whole number ratio of the atoms of each element present in a compound.

Question 12

What is general and displayed formula?

Answer 12

General formula- simplest algebraic formula for any member of a homologous series. (Can be used to generate the molecular formula)

Displayed formula-shows the relative positioning of all the atoms in a molecule and the bonds between them.

Question 13

What is structural and skeletal formula?

Answer 13

Structural formula- shows the arrangement of the atoms in a molecule and which groups are bonded together.

Skeletal formula- a simplified organic formula where you remove all carbon/hydrogen labels and bonds to hydrogen atoms:
-each line represents a single bond.
-intersection of two lines is a carbon atom.
-end of a line represents a -CH3 group.
Functional groups must be shown on skeletal formula.

Question 14

What are isomers?

Answer 14

Different compounds with the same molecular formula.

Question 15

What are structural isomers?

Answer 15

Structural isomers are compounds with the same molecular formula but different structural formulae.

Question 16

How can a covalent bond be broken?

Answer 16

homolytic fission

or heterolytic fission.

Question 17

Explain homolytic fission.

Answer 17

The breaking of a covalent bond where each of the bonded atoms take one of the shared pair of electrons from the bond.
-each atom now has a single unpaired electron.

An atom with an unpaired electron= a radical (highly reactive species)

Question 18

Explain heterolytic fission.

Answer 18

The breaking of a covalent bond where one of the bonded atoms takes both electrons.

• atom that takes electrons= negative ion.
• atom that loses electrons =positive ion.

Question 19

What is a reaction mechanism?

Answer 19

A reaction mechanism shows how the react takes place.

Curly arrows show the movement of electron pairs when bonds are formed/broken.

Question 20

What are addition, substitution and elimination reactions?

Answer 20

• Addition reaction: 2 reactant join to form one product.
• substitution reaction: atoms swap places.
• elimination reaction: involves the removal of a small molecule from a larger one. (One reactant forms two products)

Question 21

General formula for alkanes, alkenes, alcohols, carboxyl acids, ketones?

Answer 21

Alkanes= CnH2n+2
Alkenes= CnH2n
Alcohols= CnH2n+1OH
Carboxylic acids= CnH2nO2
Ketones= CnH2nO