how do we distinguish between alkanes,alkenes and alkynes by chemical method?
Answers
we can use the formula for differntiation
alkane=Cn(H2n+2)
n and 2n as subscripts
alkene=CnH2n
n and 2n subscripts
alkynes=CnHn
or we use hybridisation mtd but that is not always correct
it it is alkane it is SP3 hybridisation
if it is alkene it is SP2 hybridisation
if it is alkyne it is SP hybridisation.
ANSWER
We can basically use a variety of tests to distinguish between Alkanes and Alkenes.
Test=>
°The most Commonly used test is by using Bromine(Br) water.
-When Br water is treated in alkane no reaction takes place and the color if bromine water retains whereas in case of alkene the reaction takes place and this results in decolorizing of Bromine water.
Reactions=>
1)With Alkene
-C2H4 + Br => C2H4Br
(ethene) (decolorized water)
2)With Alkane
-C2H6 + Br => No reaction.
(ethane) (no change in colour)
Extra information
Alkane
-They are saturated hydrocarbons having single bonds.
-They don't react due to saturation.
-Example =>substitution,combustion etc
Alkene
-They are unsaturated hydrocarbons having double bonds.
-They show various reactions.
-Some are Hydrogenation, combustion etc.