organic analysis

• What is the chemical test for alkenes

  Add bromine water
• What would would happen in a positive test for an alkene?

  The solution would decolourise from orange to colourless
• What is the mechanism used in the alkene chemical test?

  electrophillic addition, going from a alkene to a halogenoalkane
• What will all alcohols react with and produce?

  Sodium, to produce a salt and hydrogen
• What is the general equation for the chemical test for all alcohols?

  R-OH + Na -> RONa + 1/2H2
• What are primary and secondary alcohols oxidised with?

  mild oxidising agents, for example acidified potassium dichromate
• What is the general equation for the chemical test for primary and secondary tests?

  RCH2OH + [O] --> RCHO
• What is the results of the oxdising test for tertiary alcohls?

  No change
• What does Fehilings solution oxidise an aldehyde to?

  A carboxylic acid
• What does a positive Fehling's test show and why?

  A red solid, as the copper (II) ions have been reduced to copper (I) ions
• What's the ionic equation for the Fehling's solution test?

  2Cu2+ (aq) + 2OH- (aq) + 2e- ->Cu2O (s) + H2O (l)
• What does Tollen's solution oxdise aldehydes to?

  A carboxylic acid
• What does a positive result for Tollen's test show and why?

  A silver mirror is produced around the outside of the test tube, as the silver (I) ions are reduced to silver metal
• What is the general equation for a positive tollen's test?


  RCOH + [O] -> RCOOH
• What is the ionic equation for a positive tollen's test?

  Ag+ (aq) + e- -> Ag (s)
• What would you add to a solution to see if a carboxylic acid is present?

  Carbonates or hydrocarbonates
• What would show a positive result in carboxylic test?

  CO2 would be released
• What is the general equation for a positive carboxylic acid test?

  2RCOOH + Na2CO3 -> 2RCOONA + H2O + CO2
• What can halogenoalkanes be hydrolysed by?

  NaOH, sodium hydroxide
• When the halgonoalkane is hydrolysed, what is released?


  a halide ion
• What is a halide ion tested with and what does a positive result show?

  Silver nitrate solution, and a precipitate of the silver halide will be observed
• What is the general equation for a positive halogenoalkane test?

  R-X + NaOH -> ROH + Na+ + X-
• What is the ionic equation for when silver nitrate reacts with a halide ion?


  Ag+ (aq) + X-(aq) -> AgX
• What is infrared spectroscopy used for?


  It is an analytical technique used to identify types of organic compounds
• What does each bond in a organic compound do?

  Vibrate at different frequencies so it absorbs different frequencies of infra-red radiation
• What is the infra-red spectrum graph of?

  % transmittance against wave number
• Wave number is proportional to...

  Frequency
• What is the fingerprint region?

  The region below 1500 cm-1. It is unique to a compound. A computer can compare the fingerprint region to a data base to identify the compound.
• Molecular ion peak

  The line with the largest m/z ratio - this peak gives the Mr of the compound
• When an organic compound passes through a mass spectrometer the spectrum that results will contain many lines. What are these lines due to?

  Fragments of the molecule
• Fragment ions

  The molecular ion breaks down producing ions with smaller mass to charge ratios
• What can high high resolution mass spectrometry measure?

  The atomic and molecular mass of a compound to 4 decimal places