Organic Chemistry
Name one condition needed for cracking?
What is the difference between alkenes and alkanes
alkenes at least one double bond between C atoms
alkanes all single bond between C atoms
If an alkane has 3 carbons, how many hydrogens will it have?
8
What is the name of the family of hydrocarbons with this general formula CnH2n+2?
Alkane
How many carbon atoms does pentane have?
5
Compounds that contain only carbons and hydrogens are called what? Give an example
Hydrocarbon; Methane, ethane, propane
Compounds with double bonds are called _____ .
Unsaturated compounds
Whats the difference between But-1-ene and But-2-ene?
But-1-ene: double bond from carbon 1=2. But-2-ene: double bond from carbon 2=3
What is the test for unsaturation?
Bromine test
What happens to the boiling point as the number of carbon atoms increases in a hydrocarbon chain?
Increases
Why do we crack hydrocarbons?
To meet supply and demand and to produce alkenes which are important in the fuel industry
What process do we use to turn ethene into ethanol?
Hydration, the addition of the elements of water across an alkene double bond
Describe what happens when butene reacts with bromine water. Why does this occur?
There is a colour change from orange brown to colourless. This occurs because there is an addition reaction (bromination) which add bromine to the structure of the hydrocarbon. This changes the properties (colour) of the solution
Give the two different types of product cracking can give.
1. An alkane with a shorter chain length and an alkene
2. Two or more alkenes and hydrogen
Products of the combustion of alcohols are:
Carbon dioxide and water
List 4 pieces of equipment we need to do cracking in the lab.
- ceramic wool
- Delivery tube
- Bung
- Bunsen valve
- Safety valve
- inverted test tube
- Water bath
What conditions are needed for hydration (catalytic addition of steam)
1. Immobilized phosphoric acid, 2. 300oC 3. 6000 kPa
Draw But-1-ene
On the board
What is a homologous series? (3 marks)
- Same functional group
- Same general formula
- Similar chemical properties
-A trend in physical properties
- Molecules add a CH2 to the chain each time
Describe how ethanol is produced from ethene. Please draw a displayed formula to show this. Give the structural formula for ethanol
The hydration of ethene. The atoms of water are added to the structure of ethene to produce ethanol. Structural formula: CH3CH2OH.
Ch3Ch2Ch2Ch3