When a colourless gas is passed through bromine water only decolourisation takes place The gas is
A. `SO_2`
B. HBr
C. HCI
D. `H_2S`

4 views

1 Answers

Correct Answer - A
`Br_2` cannot oxidise HBr or HCl.
`Br_2` oxidises `H_2S` to S.
`H_2S+Brto2HBr + S`
In the reaction, brown colour of the `Br_2` water is decolourised but milkiness due to colloidal sulphur appears.
`Br_2` oxidise `SO_2` to `H_2SO_4`
`({:(" "Br_2+H_2O,to2HBr+O),(H_2O+SO_2+O,toH_2SO_4):})/ul(Br_2+2H_2O+SO_2to2HBr+H_2SO_4)`
In this reaction only decolorization of `Br_2` takes place.

4 views

Related Questions