Chemistry Question

sci0x

Came across this question "Describe an experiment to show the oxidising properties of chlorine water with bromides. Describe and explain the colour change that occurs"

Never came across this before, was thinking it had something to do with the anion tests but clearly it doesnt. So can anyone answer it please?

chickens

Oh!! I know that one, I spill bromine on me.

It is Redox reactions of the halogens in the oxidation and reduction chapter. Cholrine water in pale green, bromine in water is orange. Both are clear when ions in water. Where chlorine and bromine ions are added orange and yellow solution is formed and bromine ions oxidised to bromine.

I not have book right now, that all I remember, hope it help.

angeldelight

sci0x wrote:

Came across this question "Describe an experiment to show the oxidising properties of chlorine water with bromides. Describe and explain the colour change that occurs"

Never came across this before, was thinking it had something to do with the anion tests but clearly it doesnt. So can anyone answer it please?

Its part of a really horrible mandatory experiment, I hated learning it. It's the one with lots of half equations to do with oxidation-reduction reactions.

You add about 2ml of chlorine water and 2ml of potassium bromide solution(colourless) in a test tube. The colour changes to orange/red so you know that bromine has been formed. Chlorine is the oxidizing agent, so it causes bromide ions to be oxidized to bromine, and it is reduced itself.
The half reactions are
reduction: Cl2 + 2electrons ---> 2Clminus
oxidation: 2Brminus ---> Br2 + 2electrons

Hope thats right, haven't looked at it since June

sci0x

ah one of the redox reactions found them in the book, no wonder I could not remmember them those look like the two most boringist pages in the book. Thanks for the help. Hope these things do not come up in the LC!