[autopsy]

Hey all.  Our professor gave us a few more problems for homework in order to help on our next test.  I got an A on my first test!! And much of the thanks goes to the help I have recieved on the forums here on my homework problems last week. This first question seems like an easy one but I want to be sure of it, the question reads. If 840 g of an ore of iron and oxygen yields 200. g of Fe, what percent is oxygen? Just looking at the problem and knowing nothing about it, I guessed that the equation would be 200/840 = .238   Which is the percent of Fe, S0 1-.238 = 76.19 % Oxygen.  But that seems a incredibly easy, and our professor normally tries to trip us up, let me know please if I have done this correctly, or incorrectly.

[Borek]

Assuming ore is JUST iron and oxygen your answer seems OK. But ratio iron/oxygen seems ridiculous.