Organic Chemistry

Question 1

What is a hydrocarbon?

Answer 1

A compound made of only hydrogen and carbon ONLY

Question 2

What type of bonding do hydrocarbons have

Answer 2

Covalent because they are both non-metals

Question 3

What is the formula for methane

Answer 3

CH4

Question 4

What is the formula for Ethane

Answer 4

C2H6

Question 5

What is the formula for propane

Answer 5

C3H8

Question 6

What is the formula for Butane

Answer 6

C4H10

Question 7

What is the general formula for a hydrocarbon

Answer 7

Cn+H2n+n

Question 8

What is are isomers

Answer 8

compounds which have the same molecular formula but different structure

Question 9

What type of bonds do alkanes have

Answer 9

Single

Question 10

What is crude oil

Answer 10

A mixture of hydrocarbons which have different chain lengths and boiling points

Question 11

Describe how fractional distillation separates crude oil into different fractions

Answer 11

The oil is heated until it is vaporised, it then goes into a fractioning column which is being heated. The hydrocarbons with longer chains have higher boiling points so ether are separated first. At the top of the column are hydrocarbons with shorter chains as they have lower boiling points.

Question 12

What is incomplete combustion

Answer 12

Burning a hydrocarbon in a limited supply of oxygen

Question 13

What is complete combustion

Answer 13

Burning a hydrocarbon in a unlimited supply of oxygen

Question 14

What are the products of incomplete combustion

Answer 14

Soot - carbon and carbon monoxide

Question 15

What are the products of complete combustion

Answer 15

Carbon Dioxide and water

Question 16

What is a homogeneous series

Answer 16

A homologous series is a family of hydrocarbons with similar chemical properties who share the same general formula.

Question 17

What are the types of oil found when crude oil is separated and their uses ( from top to bottom)

Answer 17

• refinery gasses: fuel for domestic heating and cooking
• petrol : fuel for cars
• kerosene : fuel for aircrafts
• diesel oil : fuel for some cars and trains
• fuel oil : fuel for ships and power stations
• bitumen : for roofs and roads

Question 18

Trends found in crude oil fractions as you go up the column

Answer 18

As you go up:

• boiling point decreases
• length of chain
• volatility increases
• flow increases
• ignites easily

Question 19

What does endothermic mean

Answer 19

Releases heat energy

Question 20

Describe how nitrogen oxides are formed and why they are harmful to the environment

Answer 20

When car engines get too hot, nitrogen and oxygen in the air react and float up into the atmosphere (as it is a gas) and becomes dissolved in rain which causes acid rain which can damage aquatic life and is harmful to the environment

Question 21

What does the term unsaturated mean

Answer 21

Has a double bond between carbons

Question 22

What is cracking

Answer 22

The process of breaking down long hydrocarbon molecules into smaller chains

Question 23

Alkenes are what kind of hydrocarbons

Answer 23

UNsaturated

Question 24

What are alkenes

Answer 24

Hydrocarbons that have one (or more) double covalent bond therefore considered unsaturated. They are very reactive and undergo addition reactions across their double bond

Question 25

General formula for alkenes

Answer 25

Cn H2n

Question 26

what is the name of alkene with formula C2H4

Answer 26

ethene

Question 27

what is the name of alkene with formula C3H6

Answer 27

propene

Question 28

what is the name of alkene with formula C4H8

Answer 28

butene

Question 29

alkenes react with bromine by addition reactions to form

Answer 29

dibromoalkanes

Question 30

What is the colour change when alkenes react with bromine to form dibromoalkanes

Answer 30

orange/brown to colourless

Question 31

Does bromine exist naturally in what state

Answer 31

a liquid (also DIATOMIC)

Question 32

When alkAnes and bromine react under specific conditions, the reaction can be known as a ..... reaction

Answer 32

substitution reaction

Question 33

What conditions are needed when steam reacts with alkenes

Answer 33

- 300*c - 60-70 atm - phosphoric acid catalyst

Question 34

Why do alkenes decolourise bromine water

Answer 34

- bromine that was aq now bonded to carbon

Question 35

What is a polymer

Answer 35

A polymer is a (large) molecule, made from joining together many small molecules called monomers

Question 36

what is a monomer

Answer 36

a monomer is the small molecule containing the double bond that makes up the repeated pattern found in polymers (alkene)

Question 37

What must a monomer have

Answer 37

- double bond between 2 carbons

Question 38

What does the term biodegradable mean

Answer 38

Can be broken down by action of bacteria

Question 39

Why is cracking a common industrial process

Answer 39

- because the demand for shorter hydrocarbons is much larger compared to longer chain hydrocarbons it is more efficient to crack hydrocarbons to make shorter ones that will be more useful

Question 40

When burning plastic waste, what can happen that damages the environment

Answer 40

- the release of toxic gases into the atmosphere