Organic analysis Flashcards
What is the chemical test for a halogenoalkane?
A precipitate is formed when aqueous
silver nitrate is added.
What is the chemical test for an alkene (C=C)?
Bromine water is decolourised.
What is the chemical test for a primary or secondary alcohol (-O-H)?
Acidified potassium dichromate turns
from orange to green.
What is the observation if Tollens’ reagent is added to an aldehyde?
A silver mirror is formed.
What is the observation if Fehling’s
solution is added to an aldehyde?
A brick red precipitate is formed
What is the chemical test for a
carboxylic acid (-COOH)?
Effervescence is observed when sodium
carbonate is added.
What is a molecular ion?
The ion formed when a molecule loses
one electron in mass spectrometry.
What are precise atomic or molecular
masses?
Atomic or molecular masses give to 5
or more decimal places.
What is m/z?
Mass to charge ratio, normally equal
to the mass of an ion in mass spec.
Why might a mass spectrum have more
than one molecular ion peak?
Due to the presence of isotopes (of
chlorine or bromine atoms).
What is the likely structure of an
ion fragment with m/z = 15?
[CH3]+
What is the likely structure of an
ion fragment with m/z = 29?
[CH3CH2]+
What is the likely structure of an
ion fragment with m/z = 31?
[CH2OH]+
What is the likely structure of an
ion fragment with m/z = 41?
[CH2=CHCH2]
+or [CH3CO]+
What are the likely structures of
ion fragments with m/z = 57?
[CH3CH2CH2CH2]
+ or [CH3CH2CO]
+
