Alkenes and Alkanes Flashcards
What is the formula for Alkanes?
CnH2n+2
Why are alkanes saturated?
Because all bonds are occupied and cannot be broken to form new ones.
- There isn’t a double bond with the same atom, that can be broken to form a new bond.
What is the formula for alkenes?
CnH2n
Why are alkenes unsaturated?
They can make more bonds once the DOUBLE BOND between carbons are broken.
What is an alkene + bromine reaction used for?
To test for alkenes.
How is an alkene reaction carried out with Bromine
Alkene and bromine are mixed together in a test tube.
- If alkene is present then the solution turn from orange to colourless
- Otherwise, there is no change in colour.
What is produced when alkenes and alkanes are burned with oxygen? (Oxidation)
Carbon dioxide + Water
How is addition polymerisation carried out?
Double bonds of Alkenes are broken down and new bonds are formed with monomers.
What is the formula for polymers?
(CnH2n)n
What is the result of condensation polymers?
Reactions between functional groups create water.
What is the rule between a condensation polymerisation reaction?
Two reacting monomers have to have two of their own functional groups at either end of the molecule, to create a long change of alternating monomers.
What are polymers normally which make them resistant to breaking down?
Non - Biodegradable
Why is the burning of plastics excellent and harmful?
- Produces alot of energy
- Produces alot of toxins and releases carbon dioxide
What is the advantage of recycling?
Less cure oil has to be used in the production of plastics
What is a disadvantage to recycling?
Process releases toxins into the environment
What is the formula for alcohol?
CnH2n+1OH
What is the formula for Carboxylic acids
Cn-1H2n-1COOH
How are carboxylic acids formed?
When alcohols become oxidised
How does fermentation create alcohols?
A reaction that uses yeast as a catalyst in converting carbohydrates into alcohol.
- Glucose solution is mixed with yeast
- Mixture is kept at 30-40 degrees
- Mixture is air-tight, to stop it from reacting with oxygen.
How do you obtain a concentrated amount of alcohol?
Through fractional distillation
- Ethanol has a lower boiling point than water so when the fraction is heated water stays and ethanol leaves the water as it escapes into another chamber.
What is the purpose of burning alcohol in this practice?
To see which one provides more energy.
How do you carry out the alcohol burning practical?
- Pour a constant volume of water into a copper calorimeter
- Set an alcohol spirit burner underneath the calorimeter
- Measure the mass of the spirit burner
- Set fire to the wig of the spirit burner
- Once the temperature of the water has raised by 20 degrees stop the practical
- Measure the mass of spirit burner
- Calculate the change in mass
What should you conclude after the alcohol experiment?
The most efficient fuel (alcohol) is the one that raises the temperature with the least mass change.
Order of homologous series?
METHANE ETHANE PROPANE BUTANE PENTANE HEXANE HEPTANE OXANE
