Chemistry Section 3: Organic Chemistry (COMPLETED) (introduction…
Chemistry Section 3: Organic Chemistry (COMPLETED)
Compounds in the same homologous series have the same general formula and similar chemical properties.
A hydrocarbon is a compound made up only of hydrogen and carbon.
General formula is the most simplified the ratio of molecules can be.
Saturated means something has bonded as many time as possible. Unsaturated means that more bonds can be made.
Isomers have the same general formula but different structures.
Alkanes is a homologous series with the formula CnH2n +2.
What this means is that for every one carbon there are two times the amount of hydrogens plus two more hydrogens.
Complete combustion gives carbon dioxide and water.
Incomplete combustion gives carbon monoxide and water.
In UV light bromine and methane will form bromomethane:
CH4 + Br2CH3Br + HBr
What has happened in this reaction is a bromine has taken the place of a hydrogen (substitution.)
An alkene will make its double bond into a single bond, to bond to two bromines.
addition of bromide
Bromine is added to the molecule.
All compounds in the homologous group alkenes have the general formula CnH2n.
The product made is colourless
When alkenes are put in bromine water it turns from brown to colourless (a good way of testing for alkenes.)
ethene -- ethanol
C2H4 (ethene) + H2O (steam) > C2H5OH (ethanol)
This reaction takes place at a high pressure (60-70 atm) and a high temperature (300) to make the reaction happen very quickly.
Phosphoric acid also speeds up the reaction as it is a catalyst.
Ethanol can be made by the anaerobic respiration of microorganisms.
glucose > ethanol + carbon dioxide
This happens at 30 degrees.
methods of producing ethanol
Cane sugar widely avalible/ cheap/ renewable
Impurities in the product
Done in batches
Hydrating (ethene and steam)
Crude oil (cracked to make ethene) expensive/ non-renewable
dehydration of ethanol
C2H5OH > C2H4 + H2O
ethanol > ethene + water
aluminium oxide is the catalyst for this reaction.