Organic analysis

Question 1

how do you test for alkene and the result?

Answer 1

-shake with bromine water

RESULT
-bromine water is decolourised (orange to colourless

Question 2

How do you test for haloalkanes and the result?

Answer 2

-add NaOH and warm
-acidify with nitric acid , add silver nitrate

RESULT
Precipitate of AgX
(Cl= white, Br= cream, I=yellow)

Question 3

how do you test for alcohols and the result?

Answer 3

-add acidified potassium dichromate and heat

RESULT
-orange to green for primary and secondary alcohols

Question 4

How do you test for aldehydes

Answer 4

1) Warm with Fehlings solution
2) Warm with Tollens reagent

Result:
1) blue colour turns red precipitate
2) silver mirror forms

Question 5

how do you test for carboxylic acid?

Answer 5

add sodium carbonate

RESULT
CO2 given off - effervescence

Question 6

what is meant by the term molecular ion?

Answer 6

is the molecule with one electron knocked off (It is both an ion and a free radical)

Question 7

what is high resolution mass spectrometry used for?

Answer 7

-to determine the molecular formula of a compound from the accurate mass of the molecular ion.

Question 8

what can high resolution mass spectrometry measure?

Answer 8

-can measure the mass to 5 d.p.
This can help differentiate between compounds that appear to have similar Mr (to the nearest whole number).

Question 9

what is the fingerprint region?

Answer 9

-Area of the infrared spectrum below wavenumber of 1500 cm-1

Question 10

what does Infared Spectrum determine?

Answer 10

it determines the functional groups present in organic compounds