organic analysis Flashcards
how to test for alcohols
acidified potassium dichromate can be used to distinguish between primary and secondary and tertiary
acidified potassium dichromate oxidises primary and secondary but not tertiary alcohols
if oxidised it will turn from orange to green
primary or secondary
we use fractional distillation to collect products from oxidation and then test whether an aldehyde- primary or ketone- secondary is formed
then use fehlings or tollens
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how do you make tollens reagent
silver nitrate solution- colourless
add few drops of NaOH- pale brown ppt
few drops of dilute ammonia until ppt dissolves
test for carboxylic acids
react with carbonate- to form CO2 and water when bubbled through limewater it goes cloudy
any other acid also reacts like this
IR spectroscopy uses infrared radiation to increase the … of … in a sample
vibrational energy
covalent bonds
what does the frequency of infrared radiation absorbed by covalent bond depend on
atoms that are either side of the bond
position of the bond in the molecule
what is the fingerprint region
allows us to identify specific molecules
can compare against a known library of spectra
where does the fingerprint region lie
between 500 cm- 1500 cm
extra peaks in the fingerprint region indicates that you have ….
impurities in the sample
greenhouse gases in the atmosphere absorb …
infrared radiation
what are some greenhouse gases
CO2 H20 CH4
where does infrared radiation come from
electromagnetic radiation from the sun reached the earth and is absorbed by land and sea
some of this radiating is re emitted as infrared
what is the greenhouse gas effect
these greenhouse gases absorb this radiation and re emit this back towards the earth. the covalent bonds absorb this radiation
