After drying and cooling your crucible, you determine that it has a mass of 22.2

Question

After drying and cooling your crucible, you determine that it has a mass of 22.251 grams.  You place a sample of iron in the crucible.  The overall mass of the crucible and iron is 25.182 grams.  You then burn the iron sample in the crucible. Assuming that the combustion of iron metal results in the formation of Fe2O3, what is the combined mass of the crucible and the combustion product in grams? Use correct sig figs.

I've gotten 30.632 as the answer (and tried using 4 sig figs) but I am missing something.  Any help?

Explanation / Answer

mass of iron=2.931

4Fe + 3O2 ==> 2Fe2O3

no of moles of Fe=2.931/55.845=0.0524moels

no of moles of Fe2O3 produced=0.0524/2=0.02624moles

weight of fe2o3=0.02624*159.69=4.1906grams

with crucible=4.1906+22.251=26.44162grams

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.