A 3.75-G SAMPLE OF IRON ORE IS TRANSFORMED TO A SOLUTION OF IRON(II)SULFATE, FeSO4,AND THIS SOLUTION IS TITRATED WITH 0.150 M K2Cr2O7. IF IT REQUIRES 43.7 mL OF POTASSIUM DICHROMATE SOLUTION TO TITRATE THE IRON(II)SULFATE SOLUTION, WHAT IS THE PERCENTAGE OF IRON IN THE ORE? THE REACTION IS

6FeSO4(aq)+K2Cr207(aq)+7H2SO4(aq)�¨
3Fe2(SO4)3(aq)+Cr2(SO4)3(aq)+7H2O(l)+K2SO4(aq)

2 answers

mols dichromate = M x L = ?
Use the coefficients in the balanced equation to convert mols dichromate to mols FeSO4
Convert mols FeSO4 to mols Fe then to grams Fe. g Fe = mols Fe x atomic mass Fe.
%Fe = (mass Fe/mass sample)*100 = ?
62.81%