Hydrocarbons

Question 1

What is organic chemistry

Answer 1

Organic chemistry is the chemistry of compounds based around C-H bonds

Question 2

What 4 things are so special about carbon

Answer 2

1. Carbon forms four bonds (tetrahedral).
2. Carbon forms strong, stable covalent bonds to itself and other second-row elements.
3. Carbon forms strong, covalent bonds to hydrogen.
   Carbon readily forms long chains.

Question 3

What are hydrocarbons

Answer 3

The simplest type of organic molecule.
Contain only hydrogen and carbon.
Can be saturated (alkanes) or unsaturated (alkenes, alkynes).
Can be linear, branched or cyclic

Question 4

What are alkanes

Answer 4

They contain only hydrogen and carbon and only have single bonds- carbon atoms are saturated with hydrogen

Question 5

What is the general formula of acyclic alkanes

Answer 5

CnH2n+2

Question 6

What shape are saturated carbon atoms

Answer 6

Tetrahedral

Question 7

What are the 3 ways you can draw linear alkanes

Answer 7

1. Full structural formulae
2. Condensed structural formulae
3. Skeletal (line) diagrams

Question 8

Describe skeletal diagrams

Answer 8

Every point on the line is a carbon atom, the lines represent bonds, hydrogens are mentally fitted in.

Question 9

How do you name cyclic alkanes

Answer 9

Same as linear alkanes but with the prefix cyclo-

Question 10

What is the name of a 9 carbon alkane

Answer 10

Nonane

Question 11

What is the name of an 11 carbon alkane

Answer 11

Undecane

Question 12

What is the name of a 12 carbon alkane

Answer 12

Dodecane

Question 13

What is the name a 13 carbon alkane

Answer 13

Tridecane

Question 14

What is the name of a 14 carbon alkane

Answer 14

Tetradecane

Question 15

How do you name branched alkanes

Answer 15

1. The longest carbon chain is your parent alkane.
2. The side-chain is your alkyl group (use the same naming rules for alkanes themselves but replace -ane with -yl).
3. The position of the alkyl group on the parent alkane must be clear (use lowest numbers possible)

Question 16

What are structural isomers

Answer 16

Compounds with identical formulae but the atoms are bonded in different orders

Question 17

Structural isomers always have the same properties- true/ false

Answer 17

False- structural isomers can have very different properties to one another

Question 18

What are optical isomers

Answer 18

When the carbon atoms are saturated and compounds have the same bonds to the same atoms, but in a different arrangement

Question 19

What is a chiral centre

Answer 19

If all 4 substituents around a central carbon are different . The mirror images of that molecule cannot be superimposed

Question 20

What are enantiomers

Answer 20

Two molecules which are identical except for the configuration of the chiral centre

Question 21

What is a racemic mixture

Answer 21

An equal mixture of two enantiomers

Question 22

What is the molecular formula of branched alkanes

Answer 22

CnH2n+2