Organic Chemistry

Question 1

Define molecular, displayed, structural,empirical and general formula

Answer 1

M: number of atoms of each element 
D: shows arrangement and bonds
S: arrangement carbon by carbon
E: smallest integer ratio  of atoms of each element 
G: algebraic relationship between atoms

Question 2

What are the 3 types of isomers?

Answer 2

Chain isomers-carbon chain is arranged differently
Positional isomers-the functional group is at different positions on the chain
Functional group isomers- the atoms are arranged to give a different functional group

Question 3

What is a homologous series?

Answer 3

They have: 
the same general formula
Formulas which increase by a CH2 group each time
Similar chemical properties
Trending physical properties

Question 4

What is an alkane reacting with bromine (a halogen)? What does it firm? What does it require?

Answer 4

A substitution reaction
C2H5Br + HBr
It requires UV light to break the halogen bond

Question 5

What is the byproduct when methane reacts with sufficient oxygen? And what are the issues with it?

Answer 5

Carbon dioxide

Greenhouse gas, climate change

Question 6

What is the byproduct when methane reacts with insufficient oxygen? And what are the issues with it?

Answer 6

Carbon monoxide

Poisonous, irreversibly bonds to haemoglobin

Question 7

What is the byproduct when methane reacts with very insufficient oxygen? What are the issues?

Answer 7

Carbon

Soot, bad for asthma sufferers

Question 8

What is a fuel?

Answer 8

A substance that is burnt to release (heat) energy

Question 9

Which hydrocarbons are better fuels?

Answer 9

Shorter ones because they are more volatile

Question 10

What harmful byproducts are produced from burning hydrocarbons?

Answer 10

Sulphur dioxide

Nitrogen oxides

Question 11

How are sulphur dioxides and nitrogen oxides created?

Answer 11

Sulphur dioxides: sulphur impurities in the fuel

NOXs: created when temperature is high enough for the reaction (like in car engines)

Question 12

What can the sulphur dioxides and NOXs cause? Why is this bad?

Answer 12

Acid rain

Which kills fish

Question 13

What are the features of alkanes? (4)

Answer 13

Homologous series
General formula C (n) H(2n+2)
Contain only hydrogen and carbon
Are saturated (only have single bonds)

Question 14

What is the order of prefixes?

Answer 14

Meth
Eth
Prop
But
Pent

Question 15

What are the 4 features of alkenes?

Answer 15

Homologous series
General formula C (n) H (2n)
Only made of hydrogen and carbon
Unsaturated

Question 16

What is the alkene and bromine reaction? What does it form?

Answer 16

Addition

C2H4Br2

Question 17

How can you distinguish between alkanes and alkenes?

Answer 17

Add bromine water
Alkane-stays orange without UV
Alkene-orange-brown disappears

Question 18

What is the order of the fractions from shortest to longest?

Answer 18

Refinery gases
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen

Question 19

What happens to the properties of a hydrocarbon as the chain gets longer?

Answer 19

The viscosity gets higher
The boiling point gets higher
Less useful

Question 20

What is the purpose of cracking?

Answer 20

To balance the supply—demand issue

Question 21

How do you do cracking?

Answer 21

Heat the hydrocarbon to 600-700 degrees
Pass it over a catalyst (alumina/silica)
Produces one alkane and one or more alkenes

Question 22

Define monomer and polymer

Answer 22

Monomer-small alkene molecule that can be added to others

Polymer-long, saturated molecule formed from lots of monomers

Question 23

What are the problems with polymers?

Answer 23

Unreal tube so sent biodegradable and last for 1000s if years—damage planet
Burning them gives off toxic fumes
The often aren’t reused and recycled

Question 24

How is polypropene used?

Answer 24

In ropes

Question 25

How is polytetrafluoroethene used?

Answer 25

In non-stick pans

Question 26

How is PVC used?

Answer 26

Window frames