Calculate Mass Percent of Fe in Ore Sample

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SUMMARY

The discussion focuses on calculating the mass percent of iron (Fe) in an iron ore sample weighing 0.9292g, which is dissolved in hydrochloric acid (HCl) and titrated with 30.86mL of 5.027×10−2M potassium dichromate (K2Cr2O7). The balanced chemical equation provided is 6Fe2+ + 14H+ + Cr2O72- → 6Fe3+ + 2Cr3+ + 7H2O. To find the mass percent of Fe, one must first determine the moles of K2Cr2O7 used in the titration and then use stoichiometry to calculate the corresponding moles of Fe, ultimately converting this to grams and then to mass percent.

PREREQUISITES
  • Understanding of stoichiometry and balanced chemical equations
  • Knowledge of molarity and how to calculate moles from volume and concentration
  • Familiarity with titration techniques and calculations
  • Basic skills in converting between grams and moles
NEXT STEPS
  • Calculate moles of K2Cr2O7 using the formula: moles = molarity × volume (in liters)
  • Determine the moles of Fe2+ oxidized based on the stoichiometry of the balanced equation
  • Convert moles of Fe to grams using the molar mass of iron (55.845 g/mol)
  • Calculate the mass percent of Fe in the ore sample using the formula: (mass of Fe / mass of ore sample) × 100
USEFUL FOR

Chemistry students, laboratory technicians, and anyone involved in analytical chemistry or mineral analysis will benefit from this discussion.

srana
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An iron ore sample weighing 0.9292g is dissolved in HCl(aq), and the iron is obtained as Fe2+(aq). This solution is then titrated with 30.86mL of 5.027×10−2M K2Cr2O7(aq).

6Fe2++14H++Cr2O2−7→6Fe3++2Cr3++7H2O

So how would i go about finding the mass percent of Fe in the ore sample?

I tried multiplying 30.86ml with the 5.027×10−2M K2Cr2O7(aq) to find the mol of K2Cr2O7 but I have no idea what i am doing with that..Please respond as soon as you can! thanks
 
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Can you format things a bit nicer, makes it easier to read.

Anyway, your equation is 6Fe2+ + 14H+ + Cr2O72- → 6Fe3+ + 2Cr3+ +7H2O

If you have the amount of dichromate from your titration, what does the balanced equation tell you?
 
The units of molarity are moles/liter. How many liters are there in 30.86 ml? How many moles of dichromate were consumed in the titration? How many moles of iron are oxidized per mole of dichromate titrated? How many moles of iron were in the solution? How many grams of iron were there in the solution?
 

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