Iron(ii) can be oxidized to iron(iii) by dichromate ion, which is reduced to chromium(iii) in acid solution. a 2.5000-g sample of iron ore is dissolved and the iron converted into iron(ii). exactly 19.17 ml of 0.0100 m na2cr2o7 is required in the titration. what percentage of the ore sample was iron?

% Iron in the ore = 2.57%

Explanation:

The redox reaction involving the oxidation of Fe2+ to Fe3+ in the presence of Na2Cr2O7 is:

Based on the reaction stoichiometry:

6 moles of Fe2+ requires with 1 mole of Cr2O7^2-

Moles of Cr2O7^2- required in the titration:

Therefore, moles of Fe2+ present is:

Atomic mass of Fe = 55.85 g/mol

Mass of Fe present in the ore is:

%Fe in the ore is:

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa

elements make up everything, and they combine to make compounds.

the answer is c