Organic Chemistry

Question 1

What is crude oil?

Answer 1

A finite resource made of the remains of ancient biomass (mostly plankton) that was buried in mud

Question 2

What is the formula for alkanes

Answer 2

CnH2n+2

Question 3

What are the first 4 alkanes ?

Answer 3

Methane, ethane, propane, butane

Question 4

How does fractional distillation work ?

Answer 4

• the crude oil is heated in the fractioning column and the oil evaporates and condenses at a number of different temperatures
• the many hydrocarbons in crude oil can be separated into fractions each of which contains molecules with a similar number of carbon atoms
• the vaporized oil rises up the column and various fractions are tapped off at the different levels where they condense

Question 5

What are the different fractions of crude oil, short to long molecule ?

Answer 5

Gases, petroleum gas, Naphtha, kerosene, diesel oil, heavy fuel oil, bitumen

Question 6

Used for gases from crude oil ?

Answer 6

Domestic heating and cooking

Question 7

Uses for petrol from crude oil ?

Answer 7

Car fuel

Question 8

Uses for Naphtha from crude oil ?

Answer 8

Chemicals

Question 9

Uses for kerosene from crude oil ?

Answer 9

Fuel for aircraft

Question 10

Uses for diesel from crude oil ?

Answer 10

Fuel for some cars and trains

Question 11

Used for heavy fuel oil from crude oil ?

Answer 11

Fuel for heavy ships and power stations

Question 12

Uses for bitumen for roads and roofs from crude oil ?

Answer 12

Roofs and roads

Question 13

Give some properties of long hydrocarbons ?

Answer 13

• high boiling point
• more viscous
• less volatile (don’t evaporate easily)
• less flammable

Question 14

Give some properties of short hydrocarbons ?

Answer 14

• lower boiling points
• less viscous
• more volatile (evaporate easily)
• more flammable

Question 15

Word Equation for the combustion of hydrocarbons?

Answer 15

Hydrocarbon + oxygen ~> carbon dioxide + water

Question 16

What process turns hydrocarbons into smaller more useful molecules ?

Answer 16

Cracking

Question 17

What are the 2 processes of cracking ?

Answer 17

• passing them over a hot catalyst (catalytic cracking)
• mixing them with steam and heated to a high temperature so thermal decomposition occurs (steam cracking)

Question 18

Saturation of alkanes vs alkenes?

Answer 18

Alkanes = saturated
Alkenes = unsaturated

Question 19

General formula of alkenes ?

Answer 19

CnH2n

Question 20

What bond does an alkene have to have ?

Answer 20

A double carbon=carbon bond

Question 21

What are the first 4 alkenes ?

Answer 21

Ethene, propene, butene, pentene

Question 22

What colour does bromine water turn when. Reacted with alkenes ?

Answer 22

Orange ~> colourless
Because the double bond makes it more reactive (unsaturated)

Question 23

Reaction of alkene and oxygen ?

Answer 23

Tend to burn in the air with smoky flames because of incomplete combustion (meaning carbon or carbon monoxide is formed)

Question 24

What functional group is in alcohols

Answer 24

OH

Question 25

What are the first four alcohols ?

Answer 25

Methanol, ethanol, propanol, butanol

Question 26

Reactions of methanol, ethanol, propanol and butanol ?

Answer 26

- burn in air to get ridiculous carbon dioxide and water - they dissolve in water to form a neutral solution (ph 7) - react with sodium to produce a hydrogen and a salt - react with oxidizing agents to form carboxylic acid

Question 27

Reactions of methanol, ethanol, propanol and butanol ?

Answer 27

- burn in air to get ridiculous carbon dioxide and water - they dissolve in water to form a neutral solution (ph 7) - react with sodium to produce a hydrogen and a salt - react with oxidizing agents to form carboxylic acid

Question 28

Uses of methanol ?

Answer 28

Chemical feedstock, anti-freeze, biodiesel, fuel

Question 29

Uses of ethanol ?

Answer 29

Alcoholic drinks, solvent, fuel

Question 30

How can ethanol be produced ?

Answer 30

- fermentation of sugar with yeast using renewable sources - conditions of about 35°C, anaerobic, and yeast enzyme catalyst - sugar ~> ethanol + carbon dioxide

Question 31

What functional group do carboxylic acids have ?

Answer 31

-COOH

Question 32

What are the first four carboxylic acids ?

Answer 32

Methanoic acid, ethanoic acid, propanoic acid, butanoic acid

Question 33

Reactions of carboxylic acids ?

Answer 33

- dissolve in water to produce acidic solutions - react with metal carbonates to produce carbon dioxide, a salt and water - react with alcohols in the presence of an acid catalyst to produce esters

Question 34

Example of an ester ?

Answer 34

Ethyl ethanoate

Question 35

Is carboxylic acids weak or strong acids and why ?

Answer 35

Weak acid, do not completely ionize in solution so have a higher pH (less acidic)

Question 36

Give 2 examples of polymers ?

Answer 36

Poly(ethene), poly(propane)

Question 37

What reaction is used to make alkenes into polymers ?

Answer 37

Additional polymerisation, joining small moonomers into larger polymer molecules

Question 38

What is condensation polymerisation ?

Answer 38

When monomers with 2 functional groups react and join together, usually losing small molecules such as water

Question 39

What do amino acids react to make by condensation polymerisation ?

Answer 39

- (2 functional groups of amine, carboxylic) - react to produce polypeptides - different amino acids can be combined in the same chain to produce protein

Question 40

Name some naturally occurring polymers ?

Answer 40

DNA Protein (monomer = amino acid) Starch (monomer = glucose) Cellulose (monomer = glucose)

Question 41

Structure of most DNA molecules ?

Answer 41

- 2 polymer chains - made from 4 different monomers called nucleotides in the form of a double helix