Chem toughie. Need any help at all on this question. Any help appreciated. Thanks!?

0 ⤊

Chem toughie. Need any help at all on this question. Any help appreciated. Thanks!?

The iron in a 1.375g sample containing some Fe2O3 is reduced to Fe2+ . The Fe2+ is titrated with 22.26 mL of 0.0195 M KMnO4 in an acidic solution (potassium is a spectator ion in this reaction).

Calculate the percentage of Fe in the sample.

The unbalanced equation for the reaction is
Fe2+ + MnO4- → Fe3+ + Mn2+

2007-01-23 03:07:24 · 1 answers · asked by AppleCard! 2 in Science & Mathematics ➔ Chemistry

1 answers

The balanced eqn is

5Fe2+ + MnO4- + 8H+ -> 5Fe3+ + Mn2+ + 4H2O

milliMoles of MnO4- = 22.26 x 0.0195

milliMoles of Fe2+ -> 5x22.26x0.0195

millimoles of Fe2O3 = 5x22.26x0.0195/2

Weight of Fe2O3 = 5x22.26x0.0195x160x10^-3/2

%age of Fe2O3 in sample = (5x22.26x0.0195x160)x100x10^-3/(2x1.375)

= 12.63 %

2007-01-23 03:22:52 · answer #1 · answered by ag_iitkgp 7 · 0⤊ 0⤋