Question

Hi there,

I am doing some data calculations for my lab, but I'm having some trouble.

Given:
Mass of ferrous ammonium sulfate=4.0g
Mass of K3[Fe(C204)3] 3H20 =4.53g

1. Using the above mass of ferrous ammonium sulfate, calculate the theoretical yield of the K3[Fe(C204)3] 3H20.

2.What is the shape of the complex ion?
-->Not sure how I would do this.

3. What is the oxidation state of the central metal ion?

4. What is the coordination number of the central metal ion?
3. Draw the shape of the complex ion?

Answer 1

If this is the only data you have (I posted to similar question but it had redox equations with it), then I would convert 4.0 g of the first salt to grams of the second.
4.0 x (molarmass second salt/molarmass first salt) = grams second salt. This is the theoretical yield.

I would think the shape is octahedral.

Oxidation of the central ion (the Fe) is +3. Oxalate is -2 and -2*3 = -6. K3 is +3 which leaves +3 for the Fe.

The coordination number is 6.
We can't draw structures on the board but here is a link. If it looks confusing, think of an octahedron and draw the bidentate oxalate ion to two points on the octahedron, There are three of the ox ions, so that will take up the six point of the octahedron.
http://upload.wikimedia.org/wikipedia/commons/3/33/Potassium-ferrioxalate-2D.png