Fundamentals L35

[Alyssa Ly 2G]

L.35 Sodium bromide, NaBr, which is used to produce AgBr for use in photographic film, can itself be prepared as follows:
Fe + Br2 --> FeBr2
FeBr2 + Br2 --> Fe3Br8
FeBr2 + NaCO3 --> NaBr + CO2 + Fe3O4
What mass of iron, in kilograms, is needed to produce 2.50 t of NaBr? Note that these equations must first be balanced!

Hey! I couldn't balance the 3rd equation and it doesn't seem like it can be balanced. Is Fe3Br8 supposed to be in the third equation instead of FeBr2? Thank you!

[Coline Luo 2E]

I actually had the same issue with this problem. I think that the book may have a typo so, yes, you are supposed to use Fe3Br8 instead. This allows you to balance the equation to be 1Fe3Br8 + 4Na2CO3 --> 8NaBr + 4CO2 + 1Fe3O4. Hope this helps!

[Christina Gigoux 1D]

Yes, this is one of the problems posted in the section of the website with corrections ("Solution Manual Errors" link). It is supposed to be Fe3Br8 instead.

[Sasha Gladkikh 2A]

Whenever you believe there is a potential error within a textbook exercise, refer to the "Solution Manual Errors 7th Edition" — posted on Dr. Lavelle's website. This PDF lists and corrects all textbook errors in detail.

Here is the link:
https://lavelle.chem.ucla.edu/wp-conten ... rs_7Ed.pdf

To reiterate, there is in fact an error within textbook exercise "L.35". In the third reaction step, the compound "FeBr2" needs to be "Fe3Br8".