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Flashcards in Organic Chemistry Deck (52)
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1
Q

What is the formula of alkanes?

A

CnH2n+2

2
Q

What are the first 4 alkanes?

A

Methane
Ethane
Propane
Butane

3
Q

What are the properties of a shorter chain?

A

Less viscous
More flammable
more volatile

4
Q

What is the equation for combustion?

A

Hydrocarbon + oxygen —–> carbon dioxide + water

5
Q

What happens to carbon and hydrogen in combustion?

A

They are oxidised

6
Q

How does fractional distillation work?

A

Oil is heated and turned to gas
Hottest at the bottom
Long chains at the bottom as they have higher boiling points
Shorter chains at the top as they have a lower boiling point

7
Q

Why are short chains good?

A

They are flammable so they make good fuels

8
Q

What is cracking?

A

Thermal decomposition

9
Q

How does cracking work?

A

Heat to vaporise long chain
Vapor passed over hot powdered aluminium oxide catalyst
Long chain split apart on catalyst surface

10
Q

What is another way of cracking?

A

Vaporise them
Mix them with steam
Then heat to a very high temperature

11
Q

What is the general formula for alkenes?

A

CnH2n

12
Q

What are the first four alkenes?

A

Ethene
Propene
Butene
Pentene

13
Q

What happens if you burn alkenes in the air?

A

They undergo incomplete combustion

14
Q

What is the word equation for incomplete combustion of alkenes?

A

Alkene + oxygen —–> carbon + carbon dioxide + water

15
Q

What does incomplete combustion result in?

A

Smokier flame

Less energy being released

16
Q

What happens in addition reactions of alkenes?

A

The double carbon bond opens up to leave a single bond and a new atom is added to each carbon

17
Q

What can be added to alkenes?

A

Halogens
Hydrogen
Steam

18
Q

What is the addition of hydrogen known as?

A

Hydrogenation

19
Q

What happens in hydrogenation?

A

Alkene is reacted with hydrogen in the presence of a nickel catalyst

20
Q

What would be the product of ethene + bromine?

A

Dibromoethane

21
Q

What can be used to test for alkenes?

A

Bromine water

22
Q

What happens when bromine water is added?

A

It is first orange then will become colourless when bonds are unsaturated
Forming a dibromo-compound

23
Q

When steam reacts with alkenes what is the product?

A

Alcohol

24
Q

What happens when steam is reacted with alkenes?

A

Water is added across the double bond and an alcohol is formed

25
Q

How is steam reacted with alkenes?

A

In the presence of phosphoric acid (catalyst)

26
Q

What happens after ethanol is formed?

A

Mixture is passed over a reactor to condense
Ethanol and water have a higher boiling point so they condense and unreacted ethene is recycled
Alcohol is then purified via fractional distillation

27
Q

What are polymers?

A

Long chain molecules made up of many repeating smaller molecules called monomers

28
Q

What can unsaturated monomer molecules (alkenes) do?

A

Open up their double bonds and join together to form polymer chains

29
Q

What is it called when alkenes form polymer chains?

A

Addition polymerisation

30
Q

How is addition polymerisation done?

A

Under pressure and a catalyst

31
Q

How do you draw a repeating unit?

A
Replace the double bond with a single bond
Add an extra single bond to each carbon
Fill the rest up
Put a brackets round 
Put an 'n' outside the brackets
32
Q

What is the general formula for alcohols?

A

CnH2n+1OH

33
Q

What are the four alcohols?

A

Methanol
Ethanol
Propanol
Butanol

34
Q

What are the properties of alcohols?

A

Flammable
Soluble in water
Undergo complete combustion

35
Q

Why are alcohols used as solvents?

A

They can dissolve things water can’t dissolve

36
Q

What can alcohols also be used as?

A

Fuel

37
Q

What are the conditions needed for fermentation?

A

Anaerobic
37degrees
Enzymes fro yeast
Slightly acidic

38
Q

What are carboxylic acids functional group?

A

COOH

39
Q

What are the four carboxylic acids?

A

Methanoic acid
Ethanoic acid
Propanoic acid
Butanoic acid

40
Q

What are the properties of carboxylic acids?

A

Behave as acids
Dissolve in water to produce acidic solutions
React with carbonates to produce CO2

41
Q

Whats the difference between the structure of alcohols and carboxylic acids?

A

Carboxylic acids have one more oxygen atom

42
Q

How could alcohols be turned into carboxylic acids?

A

Adding oxygen (oxidation) + oxidising agent

43
Q

What is the equation for reacting carboxylic acids with carbonates?

A

Ethanoic acid + sodium carbonate —–> sodium ethanoate + carbon dioxide + water

44
Q

How are esters formed?

A

From an alcohol and carboxylic acid

45
Q

What are the equation for esters?

A

Alcohol + carboxylic acid ——>. ester + water

46
Q

What type of catalyst is used to make esters?

A

Acid catalyst eg. sulfuric acid (concentrated)

47
Q

How is ethyl ethanoate formed?

A

Ethanoic acid + ethanol ——> Ethyl ethanoate + water

48
Q

What does condensation polymerisation involve?

A

Monomer of different functional groups

49
Q

What happens when a new bond is formed in condensation polymerisation?

A

A small molecule (water) is lost

50
Q

Number of types of monomer?

A

A- one

C- two or one with two functional groups

51
Q

Number of products?

A

A- one

C- two (polymer + small molecule)

52
Q

Functional group involved?

A

A- carbon double bond

C- two reactive groups on each monomer