A sample of ferrous sulfate and ferrous oxalate was dissolved in dil H2SO4 The complete oxidation of reaction mixture - Chemistry - Solutions

Question

A sample of ferrous sulfate and ferrous oxalate was dissolved in
dil H2SO4 The complete oxidation of reaction mixture required 40 ml
of N/15 KMnO4 after oxidation the reaction mixture was reduced by
Ninc and Sulfuric acid On again Oxidation by same KMnO4 25 ml were
required The mole ratio of
FeSO4 : FeC2O4 in sample is ??

Kumar Sarang · Accepted Answer

For FeSO4 ferrous sulphateFe2+ →Oxidation Fe3+ →Reduction Fe2+For FeC2O4 ferrous oxalateFe2+ →Oxidation Fe3+ →Reduction Fe2+C2O42-→Oxidation CO2↑Let the mM of FeSO4 and FeC2O4 be a and b respectively
Meq  of Fe2+ + Meq
 of Fe2+ + Meq  of C2O42- =Meq
 of KMnO4 used  in FeSO4                                     in FeC2O4                    in FeC2O4a×1                 +     b×1             +     b×2                   = 40 ×115 =83  a+3b =83 
 equation (1)After reduction of mixture only Fe2+ ions are  formed from Fe3+ since all CO2 escapes out in air
Meq  of Fe2+ from FeSO4 + Meq
 of Fe2+ from FeC2O4 =Meq
 of KMnO4 useda×1                                        +    b×1                                        = 25 ×115=53Thereforea+ b = 53
equation (2)Solving equation 1 and  2 simultaneously we geta =7/6b=1/2Ratio of Fe in FeSO4 and FeC2O4 = ab=73 or 7:3