Chemmistry Past paper problems...

[Diamona151294]

in Q9 part b of this paper
http://www.xtremepapers.me/CIE/Cambridg ... 4_qp_4.pdf

... i dont get why potassium magnate turns from colourless to pink and not the other way round....

Also in q11 dii of the same paper, to make an isomer can we only move the OH part and not the rest? lyk can i move one C atom on top and make the three triangular. only difference is on of the c atoms has no bonds with any other c atom. is that valid?

if any one has any chemistry tips for oxidation and reduction and other reactions can u pls post them?? i simply cant keep those straight!

please keep checking this one.. cuz ill be posting any other problems i have... and can other people also use this space? it helps to keep track of it all.

 

[adnanj]

in Q9 part b of this paper
http://www.xtremepapers.me/CIE/Cambridg ... 4_qp_4.pdf

... i dont get why potassium magnate turns from colourless to pink and not the other way round....

Also in q11 dii of the same paper, to make an isomer can we only move the OH part and not the rest? lyk can i move one C atom on top and make the three triangular. only difference is on of the c atoms has no bonds with any other c atom. is that valid?

if any one has any chemistry tips for oxidation and reduction and other reactions can u pls post them?? i simply cant keep those straight!

please keep checking this one.. cuz ill be posting any other problems i have... and can other people also use this space? it helps to keep track of it all.

it was sulfuric acid with Fe 2+ ions.. so it can be green or colourless.. then at the end point, potassium manganate was added that it purple in colour.. so it would change to purple..
hope it helped

 

[Diamona151294]

if it is originally purple then how did it change to purple? even the paper sez that its purple so how can the change be from colourless to purple? ugh!!!