[pm]

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.

[farmboy]

For atomic percentage find the total number of atoms in the sample, then find out how many of these are carbon and calculate what percentage this constitutes.  For weight find total weight of sample, then total weight of carbon and calculate what percentage this constitutes.

[pm]

could you give me a example say if the % carbon was 4.3% as this is realy not my strong point.

[pm]

0r could it be 6.7% ?

[Schrödinger]

Cementite is Fe₃C. So, what is the atomic percent?

Its molecular mass is 180. Suppose the weight of the sample is 180 grams. How many grams Fe and C are present? What is the percentage by mass of each element?

Hope this helps