Iron carbon phase diagram

I've tried calculating the percent composition of the ferrite eutectoid solid using: $$\frac{(6.67-1.09)}{(6.67-0)}=83.7\%$$ but the answer key says it should be $35.8\%$. What am I doing wrong?

  • 3
    $\begingroup$ Welcome to the site! Would you be able to copy the image of the full phase diagram into the post and then separately include the question as text? This will make it easier for other users to answer and easier for future users to find later (text in images isn't searchable). It will also help if you explain the formula you are using to calculate the percent composition. $\endgroup$
    – Tyberius
    Jan 23, 2022 at 15:51
  • $\begingroup$ At first glance, the discrepancy could be related to mol% vs weight%. Check if you get the right answer when you weigh/unweigh by the atomic masses of Fe and C? $\endgroup$ Jan 25, 2022 at 22:11


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