rganicanalysis
Testing for alcohols
acidifiedpotassiumdichromate kzer207 used mild oxidisingagent
primaryand secondaryalcohols are oxidised colourchangefromorange to
reen tertiary alcohols cannot beoxidisedusingdichromate
use fractional distillation to collect productsproduced from oxidationand
est to see if whether an aldehyde or ketone isformed
Aldehyde made fromprimary alcohol
ketone made from secondary alcohol
Test for aldehydesand ketones
Fencing's solution or Benedict's solution has similar make up
is add to test tube with productand place in a hot water bath
Aldehydes blue solution to brick red precipitate
ketones remains blue
Tollens reagent
add few dropsof Naoh to colour Espesialumemronniitargtnf
ecipitate forms add few drops of d 1 4d.fi eadfsb8fYe's
o produce Tollen's reagent
Add To lien's reagent to product in a test tube and place in a hot water bat
Aldehydes Totten's reduced to silver whichcoatsinside of test tube
ketones silver precipitate formed
hot water bath used instead of bunsen burner as aldehydes and ketones
e flammable
Test for alkenes decolouration of bromine water
addbromine water to product in a test tube and add a bung to it shake tes
ube
solution goes from brown to colourless if alkene is present
bromine water reacts with a double colourless solution formed is a
bromoalkane
test for carboxylicacids
react with carbonates to make co gas and water
e g solidsodiumcarbonate or even sodiumcarbonatesolution
when bubbledthrough limewater it turns cloudy
any other acid will react in the same way so have to perform
ther spectral techniques to confirm presence of carboxylic acid
Massspectrometry
used to find relative molecular mass Mr of a compound
m z is mass to charge ratio mass charge as most have just a 1
harge miz is same as fragment mass
peak with largest mla value is Mr of molecular parent ion with electron
mpact ionisation it is Mt 1 peak with electrospray ionsiation have to
btract 1 from Miz value to find molecular mass of molecule
High Resolution Mass spectrometry
measures relative mass to several decimalplacesunlikestandardlow
resolution
ich mayonlybe able to measure relative mass to nearest whole number
useful to differentiate between 2molecules with the same molecular mas
nearest whole number
e g 2C 12.0000 H 1 0078,160 15.9990
CH3CH0 44 0302 C3148 44.0624
Infrared IR spectroscopy
uses infrared radiation to increase vibrationalenergy of covalentbondin a
ample
frequency of infrared radiation absorbed by a covalent bonddepends on
1 atoms either side of bond
2 position of bond in the molecule
comparepeak in IR spectrum to databooklet values
Testing for alcohols
acidifiedpotassiumdichromate kzer207 used mild oxidisingagent
primaryand secondaryalcohols are oxidised colourchangefromorange to
reen tertiary alcohols cannot beoxidisedusingdichromate
use fractional distillation to collect productsproduced from oxidationand
est to see if whether an aldehyde or ketone isformed
Aldehyde made fromprimary alcohol
ketone made from secondary alcohol
Test for aldehydesand ketones
Fencing's solution or Benedict's solution has similar make up
is add to test tube with productand place in a hot water bath
Aldehydes blue solution to brick red precipitate
ketones remains blue
Tollens reagent
add few dropsof Naoh to colour Espesialumemronniitargtnf
ecipitate forms add few drops of d 1 4d.fi eadfsb8fYe's
o produce Tollen's reagent
Add To lien's reagent to product in a test tube and place in a hot water bat
Aldehydes Totten's reduced to silver whichcoatsinside of test tube
ketones silver precipitate formed
hot water bath used instead of bunsen burner as aldehydes and ketones
e flammable
Test for alkenes decolouration of bromine water
addbromine water to product in a test tube and add a bung to it shake tes
ube
solution goes from brown to colourless if alkene is present
bromine water reacts with a double colourless solution formed is a
bromoalkane
test for carboxylicacids
react with carbonates to make co gas and water
e g solidsodiumcarbonate or even sodiumcarbonatesolution
when bubbledthrough limewater it turns cloudy
any other acid will react in the same way so have to perform
ther spectral techniques to confirm presence of carboxylic acid
Massspectrometry
used to find relative molecular mass Mr of a compound
m z is mass to charge ratio mass charge as most have just a 1
harge miz is same as fragment mass
peak with largest mla value is Mr of molecular parent ion with electron
mpact ionisation it is Mt 1 peak with electrospray ionsiation have to
btract 1 from Miz value to find molecular mass of molecule
High Resolution Mass spectrometry
measures relative mass to several decimalplacesunlikestandardlow
resolution
ich mayonlybe able to measure relative mass to nearest whole number
useful to differentiate between 2molecules with the same molecular mas
nearest whole number
e g 2C 12.0000 H 1 0078,160 15.9990
CH3CH0 44 0302 C3148 44.0624
Infrared IR spectroscopy
uses infrared radiation to increase vibrationalenergy of covalentbondin a
ample
frequency of infrared radiation absorbed by a covalent bonddepends on
1 atoms either side of bond
2 position of bond in the molecule
comparepeak in IR spectrum to databooklet values
