The amount of iron in steel can be determined by titration with dichromate. first, the steel is dissolved in hydrochloric acid to oxidize all the iron to fe 2 + . an indicator is added that will react with excess dichromate. then, potassium dichromate is added to the solution until the end point is reached. cr 2 o 2 − 7 + 6 fe 2 + + 14 h + ⟶ 2 cr 3 + + 6 fe 3 + + 7 h 2 o for the analysis of 2.00 g of steel, the titration required 21.20 ml of 0.1800 m k 2 cr 2 o 7 . what was the mass percentage of iron in this steel sample?