why can't we have isomers of the first three members of the alkane series

we cant have isomers of the first three members of the alkane series because of the following laws of isomers:-

1. the parent chain should have the most number of carbon atoms.

2. the branching cannot be done from the first or the last atom carbon atom of the structure.

now because of these laws we can see that with methane it is certainly not possible, with ethane it is not possible either as the branching is happening from only one carbon atom and violates both the laws,..... now propane cannot do the same as the branching is either going to happen from the first or the last carbon atom of the parent chain....

thus we can say that the first three members of the alkane series cannot have isomers...

parent chain means the basic chain on which the branching is to take place...

  • 119
In first three member of alkane series,branching is not possible.
  • -14
Isomers are the organic compounds having same molecular formula but different structures. Different arrangement of carbon atoms is possible only if the hydocarbons have 4 or more carbon atoms.Therefore we cannot have isomers of first three members of alkane series.  
  • 35
we can write isomers to the compounds that can also be written in branched manner....since the first 3 members of alkanes (i.e CH4..C2H6...C3H8) cannot be written as isomers as it cannot be written in branched manner
  • 3
Because if we make the isomer of first three element the formula get changed which is not possible
  • -9
It is because isomers are identical formula , but with different structure. but we donot find in alkene isomers
  • -13
see how our scinence teacher have answered this question

  • 0
Still v can write propane as 2methyl ethane and also propane with that makes 2 isomers
  • -13
Because there is no branching possible for first three members, i.e., carbon atoms remain linked in one chain only and there is no possibility of formation of side chain.
  • 2
For formation of isomers atleast 3 carbon atoms are essential. The first 3 members of alkanes have less than 4 carbon atoms thus isomers cannot be formed.
  • -3
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