ORGANIC CHEM

• To test for alkenes, you use bromine water and a positive test would show colour change from orange to colourless
• Alkenes are used to produce polymers and other chemicals like solvents
• The products of cracking are alkanes and alkenes
• Test for carbon dioxide: Pass gas through limewater and positive test would be that it turns cloudy,milky white, turbid. This cloudiness is due to insoluble calcium carbonate.
• Test for water 1: Add liquid to anhydrous, white copper sulfate and if it turns blue, water is present
• Test for water 2: Add liquid to blue cobalt chloride, if it turns pink, the liquid is water.
• Volatility is tendency to turn into gas.
• Viscosity is how easily it flows
• Alkenes react with hydrogen to produce alkanes at 60ºC in presence of nickel catalyst
• Alkenes react with steam to produce alcohols
• ALCOHOL GENERAL FORMULA: CnH(2n+1)OH
• Carboxylic acids contain a C=O bond
• Carboxylic acid general formula:CnH2n+1COOH
• Carboxylic acids are different from other acids because they react with alcohols to produce esters and water in the presence of an acid catalyst.
• Cabroxylic acids are weak acids because they don't completely ionise and molecules remain in solution.
• Carbon dioxide is given off more slowly when carboxylic acids react with metal carbonates as compared to hydrochloric acid of same concentration, this is due to them being weak acids
• Esters functional group: -COO
• Esters are volatile compounds and have distinctive smells.
• Example of ester is ethyl ethanoate and has structural formula CH3COOCH2CH3
• Alcohols can be oxidised by chemical oxidising agents like potassium dichromate to produce carboxylic acids
• Many organic compounds dissolve in alcohols so alcohols are used in mouth washes and perfumes
• Some microbes in air can oxidise solutions of ethanol to produced ethanoic acid which turns alcoholic drinks and is the main acid in vinegar.
• When burnt completely, alcohols produce carbon dioxide and water
• Alcohols are highly flammable and burn with clean blue flame
• Methanol and ethanols are used in fuels mixed with petrol due to the high flammability
• When sodium and ethanol react, sodium will efferversce and hydrogen gas will be produced, but less rigourous than sodium and water
• glucose monomers -> starch polymers + water
• glucose monomers -> cellulose polymers + water
• Naturally occuring polymers: starch, cellulose, proteins
• Glucose is monosaccharide (made of 1 sugar unit). Monosaccharide sugars make polysaccharides.
• variety of amino acid monomers -> protein polymers + water
• Monomers of proteins are amino acids
• Amino acids have 2 functional groups in molecule: basic amine group (-NH2) and carboxylic acid group (-COOH)
• Simplest amino acid is glycine
• Many glycine molecules link together in a condensation reaction to form a polypeptide molecule
• DNA is made by condensation polymerisation
• DNA is made up of repeating units of nucleotides (monomers) so it's known as a polynucleotide.
• DNA molecules contains a double helix structure made up of 2 polymer strand running in opposite directions.
• DNA is made from 4 different nucleotides consisting of amino acids attached to deoxyribose (sugar) and phosphate group.
• Nucleotides join by forming covalent bonds between sugars of 1 nucleotide and phosphate of another.