Page 35 - 6641

The isolated ethen is passed into a test tube with
bromine water, which is rapidly discolored due to the
addition of bromine in the place of double bond with the
formation of 1,2-dibromoethane:

CH CH + Br 2 CH 2 CH 2
2 2
Br Br

1,2-dibromoethane
1,2-dibromoethane

When passing ethane through aqueous solution of
potassium permanganate, the violet coloration of KMnO 4
gradually disappears and a brown precipitate of MnO 2 is
formed, indicating the oxidation of the ethane by the
reaction:

4
2
3 CH CH + 2KMnO + HO 3 CH CH +2 MnO + KOH
2
2
4
2
2
2
2

OH OH
1,2-ethanediol

If the ethen is ignited at the end of the gas-duct, then
there is
a bright flame. The reaction of ethen burning is
written as follows:

ethane Н 2С=СН 2 + 3О 2 → 2СО 2 + 2Н 2О
Н 2С=СН 2 + 3О 2 → 2СО 2 + 2Н 2О↑

ethеne