More redox titration questions help needed

http://imgur.com/a/z8g45
Hi, for this question have I done it correctly for both part a and part b? http://imgur.com/9BUI3cl
My second question is that I am unsure what the information highlighted in orange is for? Is this used to work out the concentration of the Fe2+ ions, although this is not the question.

Reply 1

coconut64

OP

16

My third question is that I would like to know if I have obtained the right answer for this question. I got 25.5%. Thanks.

(edited 7 years ago)

Original post by coconut64

My third question is that I would like to know if I have obtained the right answer for this question. I got 25.5%. Thanks.

It's a stupid question.

You know the relative atomic mass of copper = 63.5
You know the relative mass of hydrated copper(II) sulfate = 249.5
Therfore percentage of copper = 100 * 63.5/249.5 = 25.5

There is absolutely no need for the titration.

Original post by coconut64

http://imgur.com/a/z8g45
Hi, for this question have I done it correctly for both part a and part b? http://imgur.com/9BUI3cl
My second question is that I am unsure what the information highlighted in orange is for? Is this used to work out the concentration of the Fe2+ ions, although this is not the question.

The oxidation is carried out in acidic conditions (look at the equation for the redox processes) so the salt is dissolved in excess acid to ensure that there are enough hydrogen ions.

Reply 4

an_atheist

15

Original post by charco

It's a stupid question.

You know the relative atomic mass of copper = 63.5
You know the relative mass of hydrated copper(II) sulfate = 249.5
Therfore percentage of copper = 100 * 63.5/249.5 = 25.5

There is absolutely no need for the titration.

You've missed the point. That's the theoretical value, in a pure sample.