Question

position of double bond in alkenes is identified by which test?

Answer 1

As the position of the double bond is indicated by placing the lower of the pair of numbers assigned to the  double‐bonded carbon atoms in front of the name of the alkene. 

Answer 2

under normal conditions bromine is a toxic yellow orange liquid.Alkenes react easily summing bromine to the C-C double bonds originating brominated hydrocarbons which are colourless.on the other side saturated hydrocarbon don't react easily with halogens so it's possible to detect alkenes by observing a colour change in bromine when an organic compound is mixed with it.If the solution goes colourless presence of double bond is detected.
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