chemistry

posted by .

The amount of Fe in a 2.0008 g sample of an iron ore was determined by a redox titration with K2Cr2O7. The sample was dissolved in HCl and the iron brought to a +2 oxidation state. Titration required 26.48 mL of 0.034 M K2Cr2O7. Calculate the iron content as %w/w Fe2O3.

Cr2O72- + 14H+ + 6Fe2+ → 2Cr3+ + 7H2O + 6Fe3+

hint: Remember you are looking for Fe2O3 (2 mols of Fe)

  • chemistry -

    mols Cr2O7^2- = M x L = ?
    Convert moles Cr2O7^2- to mol Fe.
    mols Fe = mols Cr2O7^2- x (6 mol Fe/1 mol Cr2O7^2-) = ? (from the equation)
    Convert to moles Fe2O3.
    mol Fe x (1 mol Fe2O3/2 moles Fe) = ?
    g Fe2O3 = moles Fe2O3 x molar mass = ?
    %Fe2O3 = (mass Fe2O3/mass sample)*100 = ?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Redox Titration questions!

    Oh goodness, I'm such a pain! I need some help with these! How do I calculate the percentage?
  2. College Chemistry

    an iron ore sample was dissolved in Hydrochloric acid the iron was obtained as Fe2+. The solution was titrated with 41.08 mL of a 0.458 M solution of Ce+. Calculate the mass of iron in the original ore sample.
  3. chemistry

    A 0.1943g iron ore sample was dissolved in hydrochloric acid and the iron was obtained as Fe 2+ (aq). The iron solution was titrated with Ce 4+ solution according to the balanced chemical reaction shown below.After calculation, it …
  4. Chemistry

    Alcohol levels in blood can be determined by a redox titration with potassium dichromate according to the balanced equation: C2H5OH(aq) +2Cr2O7-2 (aq) + 16H+(aq)---> 2CO2 (g) + 4 Cr3+ (aq) + 11H2O (l) What is the blood alcohol level …
  5. chem lab

    KMn04 with iron(II) ammonium sulphate hexahydrate-redox titration. 1-what is the purpose of adding H2SO4 to iron sample before the titration?
  6. chemistry

    The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 6.35-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing …
  7. Chemistry

    1.630 g of iron ore is dissolved in an acidic solution. This solution is titrated to a pink endpoint with 27.15 mL of a 0.020 M KMnO4 solution. a. How many moles of MnO4- ions were consumed?
  8. Analytical chemistry

    an 0.5031 gram sample of iron ore is determined through redox titration using K2Cr2O7. The sample was dissolved in HCl and all the iron was converted to the 2+ state. Titration to the endpoint required 24.34 mL of 0.01887 mol/L K2Cr2O7. …
  9. Chemistry

    A 0.446-gram sample of iron ore is dissolved in HCl and the iron (Fe solid) is reduced to Fe2+. The solution is then titrated by 38.6mL of 0.105 N KMn)4. Calculate the percentage of Fe in the iron ore sample.
  10. Chemistry

    The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 7.79-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing …

More Similar Questions