Chemistry Paper 2
Whats the process used in cracking?
Heavy fraction heated to vaporised hydrocarbons, then it's passed over a hot catalyst or mixed with steam and heated to a very high temperature
Complete combustion of a hydrocarbon products are:
Carbon dioxide and water
Test for carbon dioxide
Turns limewater cloudy when carbon dioxide is bubbled through it
Test for water
Blue cobalt chloride paper pink
General reaction of alkenes and water
Alkene+water => alcohol
Alkenes reacting with bromine
Alkene will take the colour out of bromine
Alkenes reacting with hydrogen
60oC in the presence of a Nickel catalyst - increases boiling point
Alcohol functional group
-OH
Carboxylic acid functional group
-COOH
Esters functional group
-COO- (replace H atom in -COOH with a hydrocarbon)
What are the 2 ways to make an alcohol
-Alkene with steam in the presence of a catalyst
-fermentation of sugars with yeast in warm, anaerobic conditions
Complete combustion of alcohols
Alcohol+oxygen => carbon dioxide+water
Alcohol reacting with sodium
Sodium+ethanol => sodium ethoxide+hydrogen
Oxidation of alcohols
Alcohol+oxidising agent => carboxylic acid+water
How to make esters
Carboxylic acid+alcohol => ester+Water (acid catalyst)
What are the two amino acid functional groups?
-the amine group, - NH2
-the carboxylic group, - COOH
-simplest amino acid is glycine
Whats a mixture designed to be a useful product?
Formulation
Test for hydrogen
'squeaky pop test', lighted splint 'pops'
Test for oxygen
A glowing splint relights
Test for chlorine
Damp blue litmus paper turns white (as it gets bleached)
Test for carbonates
Add dilute acid - produces CO2
Test for Halides
Add nitric acid, then add silver nitrate solution - precipitate of silver halide forms (chlorine=white, bromide=cream, iodide=yellow)
Test for sulfates
Add hydrochloric acid, add barium chloride solution - produces white precipitate of barium sulfate
Flame test for lithium
Crimson
Flame test for Sodium
Yellow
Flame test for Potassium
Lilac
Flame test for Calcium
Orange-red
Flame test for Copper
Green