Chemistry p3 help!

[breakheart]

http://www.xtremepapers.me/CIE/Cambridg ... 4_qp_3.pdf

look at qs4..part b..ii..
i dont understand the answer. what is the theory behind it etc. plz explain

 

[xIshtar]

Right, the oxidation state of iron denotes the number of valency electrons. This is not always the case, but it is so with iron. So, as there is one less electron, only 2/3 of the volume used in the first one would be needed, so it would level off at 8cm^3

Hope I helped

 

[breakheart]

but less volume of that? iron2..?
but since less volume is used. wont the height of the precipitate be less?

 

[xIshtar]

but less volume of that? iron2..?
but since less volume is used. wont the height of the precipitate be less?

Yes, The height of the ppt will be at 2/3s of what it was, the overall volume used will be the same.