Answer:
3.12g FeO3
14.33g MgCO3
5.92g Ca(OH)2
Step-by-step explanation:
For the first problem, convert grams of Fe to mols of Fe.
molar mass of Fe: 55.845
Grams of Fe: 3.4g
3.4/55.845 = 0.06 mol Fe
There are 4 Fe for every 2 FeO3
So.. 0.06(2/4) = 0.03 mol FeO3
Multiply the mols by the molar mass of FeO3
Molar mass of FeO3: 103.845
0.03 * 103.845 = 3.12 g FeO3