Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > P2 - Organic Chemistry > Flashcards

P2 - Organic Chemistry Flashcards

1
Q

Define alkane

A

The simplest type of hydrocarbon you can get. They are saturated compounds so each carbon is attached to four hydrogen’s by single covalent bonds.
Formula: C n H 2n+2

Methane, Ethane, Propane, Butane, Hexane, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the properties of short hydrocarbon chains?

A
  • Less viscous (more runny)
  • More volatile (e.g. lower boiling points)
  • More flammable
  • Stored under pressure as liquids in bottles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the properties of long hydrocarbon chains?

A
  • More Viscous (less runny)
  • Less volatile
  • Less flammable
  • High boiling points
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens in complete combustion?

A

This is when a hydrocarbon reacts with oxygen to form carbon dioxide and water vapour. Both the carbon and hydrogen are oxidised during the reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the equation for complete combustion?

A

Alkane + oxygen —> carbon dioxide + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define crude oil?

A

It is a fossil fuel made of the remains of plants and animals, mainly plankton, that died millions of years ago and were buried in mud. With high temperature and pressure this turned into crude oil which can be drilled up from rocks where it’s found. It is a non-renewable fuel and a finite resource, meaning it will run out one day.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does fractional distillation of hydrocarbons work?

A

You heat crude oil and and the gas given off enters a fractionating column. At the bottom of the column it is very hot, and at the top it is cooler. The longer hydrocarbons with high boiling points condensed into liquids at the bottom of the column. Whereas the shorter ones with lower boiling points condense at the top.

The 6 main fractions:

  1. Refinery gas (3 carbons)
  2. Petrol (8 carbons)
  3. Kérosène - plane fuel (15 carbons)
  4. Diesel oil (20 carbons)
  5. Heavy fuel oil (40 carbons)
  6. Bitumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do you crack long chains of hydrocarbons?

A

Catalytic Cracking - vaporise, pass over hot powdered aluminium oxide catalyst.

Steam Cracking - vaporise, mix with steam, heat at high temperature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you create a chemical equation for cracking?

A

Long-chain hydrocarbon —> shorter alkane + alkene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define alkene

A

These are unsaturated hydrocarbons that have. Double bond between two of their carbon atoms meaning it has fewer hydrogen’s than an alkane. They are much more reactive than alkanes.

Formula: CnH2n

Ethene, Propene, Butene, Pentene, Hexene, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define incomplete combustion

A

When there isn’t enough oxygen in the air, alkenes produce not only carbon dioxide and water, but also carbon molecules and carbon monoxide. You can see the reaction by a smoky yellow flame, and less energy is released.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the equation for incomplete combustion?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Functional group of an alkene?

A

C=C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define hydrogenation

A

When hydrogen reacts with an alkene to open up the double bond and form an alkane:

R H H H
\ / | |
C=C + H2 —> R - C - C - H
/ \ catalyst | |
H H H H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you form an alcohol?

A

React an alkene with steam to open up the double bond and form an alcohol:

H H H H
\ / | |
C=C + H2O —> H - C - C - O - H
/ \ catalyst | |
H H H H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Functional group of an alcohol?

A

-OH

17
Q

How do halogens react with alkenes?

A

They react in addition reactions where the double bond opens up and the halogen connects to the two free double bonds:

H H H Br
\ / | |
C=C + Br2 —> H - C - C - H
/ \ | |
H H Br H

^this is dibromoethane (di=2 bromines)

18
Q

What happens to the solution when you add bromine water to an alkene?

A

It goes colourless

19
Q

How do you create addition polymers?

A

Through addition polymérisation you can put lots of alkene monomers together to open up their double bonds, and form polymer chains.

    H   H                   H    H
     |    |                     |      |
n(C=C)   —>   -(C - C)-
     |    |                     |      |
    H   H                   H    H    n
20
Q

What are the properties of alcohols?

A
  • Flammable
  • Undergo complete combustion
  • React with sodium
  • Can be oxidised by reacting with oxygen to form a carboxylic acid
21
Q

Define fermentation

A

When an enzyme in yeast converts sugars into ethanol used in alcoholic drinks.

Sugar —> ethanol + carbon dioxide
yeast

22
Q

Functional group of a carboxylic acid?

A

-COOH

      O
     //
- C
     \
      OH
23
Q

What do the names of carboxylic acids end in?

A

-anoic acid

24
Q

What is produced when a carboxylic acid reacts with a carbonate?

A

A salt, water and carbon dioxide.

The salt ends in -anoate (e.g. methanoate)

25
Q

What happens when carboxylic acids dissolve in water?

A

They ionise and release H+ ions resulting in a weak acidic solution.

26
Q

How are esters formed?

A

By reacting an alcohol with a carboxylic acid using an acid catalyst:

Alcohol + carboxylic acid —> ester + water

   H      O                    H    H                               H      O                                  H
    |      //                      |      |                                |      //                                   / H - C - C      +   HO - C - C - H   —>     H - C - C       H     H          +  O
    |       \                       |      |          acid             |       \        |      |                  \
   H       OH                H     H      catalyst        H       O - C - C - H           H
                                                                                                |     |
                                                                                               H    H
27
Q

Define condensation polymerisation

A

Unlike addition polymerisation the monomers used in condensation polymerisation have different functional groups. They react together and form bonds between them. With each new bond some molecules are lost and form water at the end. Each monomer needed to complete the reaction have to have two of the same functional groups on either side of it.

Polyester:

                                         O                O                                      O              O
                                         ||                ||                                       ||              || n  HO - [    ] - OH  +  n  C - [     ] - C    —>   -(-[     ]- O - C -[     ]- C - O -)-   + 2nH20
                                         |                  |                                                                         n
                                      OH              OH

[ ] = represents the carbon chain

Diol + Dicarboxylic acid —> condensation polymer + water

28
Q

What is the difference between addition and condensation polymerisation?

A

Addition - one monomer type, one product formed, C=C monomer

Condensation - two monomer types each with 2 of same functional group or one monomer with two different functional groups, two products, two functional groups on each monomer.

29
Q

How many functional groups does an amino acid have?

A

Two - a basic amino group (NH2) and carboxyl group (COOH)

H       H      O
  \       |      //
  N - C - C
  /       |       \
H      H       OH

Glycine

30
Q

How are polypeptides formed by condensation polymerisation?

A

The amino group of an amino acid can react with other amino groups to form a polymer chain. Every new bond formed causes water to be lost.

H H O H H O
\ | // | | ||
n N - C - C —> -(-N - C - C -)- + nH2O
/ | \ |
H H OH H n

31
Q

What kind of polymer chain is DNA made of?

A

Two polymer chains of nucleotides

Chemistry (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions