Hydrocarbons 2 Flashcards
Halogens react with Alkanes to make Haloalkanes methane + bromine —->
uv light methane + bromine —-> bromomethane + hydrogen bromide
Halogens react with Alkenes to make Haloalkanes ethene + bromine —->
ethene + bromine —-> di bromoethane
Alcohols have the functional group OH Name 2 ways to make ethanol.
phosphoric acid 1. Ethene + steam —> ethanol 2. Fermentation Yeast Glucose. —> Ethanol + CO2
Advantages and disadvantages of using fermentation method to produce ethanol
Advantages glucose is a renewable source (from sugar cane) Yeast is easy to grow Disadvantages ethanol made is not very concentrated and needs distilling to increase strength (like in whisky distillaries)
What conditions do we need for fermentation to produce ethanol?
about 30 deg temp (yeast contains an enzyme) Anaerobic (oxygen converts ethanol into ethnic acid (vinegar, yuck!)
Advantages and disadvantages of using the ethene and steam method to produce ethanol
ethene comes from crude oil which is non-renewable
What conditions do we need for ethene and steam to produce ethanol?
a catalyst of phosphoric acid high temp 300 deg high pressure 65 atmospheres
What is the functional group of carboxylic acids?
COOH
Carboxylic acids react like all acids to make salt + water. What is the name of the salt made by reacting ethanoic acid and sodium carbonate?
ethanoic acid + sodium carbonate–>sodium ethanoate + water + CO2
What is the functional group of an ester?
COO
How do we make an ester?
ethanoic acid + ethanol —> ethyl ethanoate + water
What is an addition polymer?
Made by joining unsaturated molecules of alkenes
How do you draw the repeat unit of a polymer?
remove double bond and replace with single put brackets round whole molecule add the single bonds on left and right write n at bottom right of bracket
Why are most polymers hard to get rid of?
They are inert and don’t react easily because carbon-carbon bonds are very strong takes a long time to biodegrade During them releases toxic gases Best to reuse them not dispose of them
Give an example of a condensation polymer?
polyester
- Describe how you can draw the repeat unit of a polymer
- First one is going from double bond to single bond
- Brackets outside and ‘n’ bottom right
- Second one is going from a polymer to monomer
- But in the double bond and write the ‘n’ on the left
