# Homework Help: Fe3C Cementite HELP PLEASE

1. May 20, 2010

### p.mather

Fe3C Cementite HELP PLEASE!!!!

Hello... I was wondering if someone would be able to help with the follow question...

Cementite: consider cementite. Calculate the amount of carbon in Cementite (1) as atomic % (2) as weight % [atomic weights Fe 56, c 12]. Place cementite on the Fe-C phase diagram; explain the nature of its appearance on the diagram, and comment on the nature and properties of cementite. Cementite is a key part of pearlite- how does it contribute to the structure of pearlite?

I totally understand the question apart from the atomic % and the weight %, if someone could help i would be so grateful, thanks.

2. May 20, 2010

### chemisttree

Re: Fe3C Cementite HELP PLEASE!!!!

The formula is Fe3C. That is three iron atoms per carbon. Express that ratio in terms of atoms Fe:total atoms in the formula to get Fe atomic %. Also find C:total atoms in the formula to get C atomic %. Convert that to weight to get Weight %.

3. May 20, 2010

### p.mather

Re: Fe3C Cementite HELP PLEASE!!!!

could you give me a example as this realy isnt my strong point, thanks

4. May 23, 2010

### Redbelly98

Staff Emeritus
Re: Fe3C Cementite HELP PLEASE!!!!

Fe3C contains ___ iron atoms, ___ carbon atoms, and ___ atoms in total.
Using those numbers, what percentage of the total atoms are carbon?