Organic chemistry Flashcards
Crude oil is a mixture of what?
Very large number of compounds
What are most of the compounds in crude oil?
Hydrocarbons
How can the hydrocarbons be separated?
They can be separated into fractions, each of which contains a similar amount of carbon atoms, by evaporating the oil and allowing it to condense at a number of different temperatures. This process is called fractional distillation
(look at book for diagram)
Most of the Hydrocarbons in crude oil are saturated what are they called?
Alkanes
What is the general formula alkanes?
Cn H2n+2
what are all of the bonds in a saturated Hydrocarbon?
All the bonds are single covalent bond
How else can Alkanes been shown?
C2H6 or
H H
| |
H—————C————C—————H
| |
H H
What do we know that changes as the hydrocarbons get bigger?
The boiling points increase
The viscosity increases
The flammability decreases and they give of a lot more smoke
How do you name the Alkanes?
- METHANE
- ETHANE
- PROPANE
- BUTANE
- PENTANE
- HEXANE
- HEPTANE
- OCTANE
- NONANE
- DECANE
So what would an alkane with 6 carbon atoms and 14 hydrogen atoms be called?
Hexane
What would an alkane be called with 1 carbon atom be called?
METHANE
What are Alkanes usually used for?
Fuels
What are some of the advantages of using a biofuel?
- they are renewable
- they do not have a big affect on the environment
- They have a low carbon foot print
Can hydrocarbons be broken down further?
Yes it is called cracking. This involves using a lot of heat to vaporise them. The vapours are then passed over a catalyst so the thermal decomposition can occur
What are the products of cracking?
Alkanes and unsaturated hydrocarbons
What are the names of the unsaturated hydrocarbons?
Alkenes
What is the general formula for alkenes?
CnH2n
What type of bonds are in the Alkenes?
All Alkenes contain one double covalent bond between 2 carbon atoms
What is another way of representing the Alkenes?
C3H6
H H H
| | |
H—— C—————C========C
| |
H H
======= is the double bond
What happens when Alkenes mix with bromine water?
The solution is turns from orange to colourless
How can ethanol be produced?
By reacting ethene with steam in the presence of a catalyst
How do you show the polymerisation process?
H H ⎛ H H ⎞
| | ⎜ | | ⎜
n C ==== C —————-> —— C——-C ——
| | ⎜ | | ⎜
H H ⎝ H H ⎠ n
ethene poly(ethene)
What function group do all alcohols contain?
-OH
What are the first 3 alcohols?
METHONAL, ETHONAL, PROPANOL
How do you represent alcohols?
CH3CH2OH
H H
| |
H---------C-----------------------C---------O---------H
| |
H H
What are some of the properties of the first 3 alcohols?
- dissolve in water
- react with sodium
- burn in air
- are used as fuels or solvents
- alcoholic drinks
What function group do carboxylic acids contain?
-COOH
What is the structures for Carboxylic acids?
CH3COOH
H
|
H————C————–C=======O
| |
H O———–H
How is ethanoic acid formed?
By ethanol being oxidised
What are some of carboxylic acids properties?
- Dissolve in water to produce acidic solutions
- react with carbonates to produce carbon dioxide
- React with alcohols on the presence of an acid catalyst to produce esters
- Do not ionise completely when dissolved in water and are weak acids
What is the functional group of an ester?
-COO-
How do you represent an ester?
CH3COOCH2CH3
H O H H
| || | | H--------------C-----------C----------O-----------C---------C-----------H
| | |
H H H
What are esters used for?
They are used as flavourings or perfumes
How are esters formed?
When a Carboxylic acid reacts with an alcohol
