Category: Chemical Engineering Math
"Published in Newark, California, USA"
A sample of iron ore weighing 385.6 mg was dissolved in acid and passed through a Jones Reductor. If the resulting solution required 52.36 mL of 0.01436 M K2Cr2O7 for titration, calculate the % Fe3O4 (231.55 g/mole) in the ore sample.
Solution:
The given word problem is about oxidation reduction reaction or redox in short. If a sample of iron ore is dissolved in an acid and passed through a Jones Reductor, then iron metal is converted into ferrous ion. In order to get the amount of ferrous ion in a solution, K2Cr2O7 solution is used for titration as follows
The amount of ferrous ion or iron in a sample is
The amount of Fe3O4 in a sample of iron ore is
Hence, the weight of Fe3O4 in a sample of iron ore is
Therefore, the weight percent of Fe3O4 in a sample of iron ore is
Category: Chemical Engineering Math
"Published in Newark, California, USA"
A 240 mg sample of pyrolusite was treated with excess KI. The iodine liberated required 46.24 mL of 0.1105 M Na2S2O3 solution. Calculate the % MnO2 in the sample.
Solution:
The given word problem is about oxidation reduction reaction or redox in short. The given sample which is pyrolusite contains MnO2 and then treated with excess KI. Na2S2O3 solution is used to titrate the liberated iodine. Sulfuric acid is added as a catalyst as follows
In order to get the amount of iodine liberated, Na2S2O3 solution is used to titrate the iodine crystals as follows
The amount of iodine liberated or iodine crystals is
The amount of MnO2 is
Hence, the weight of MnO2 in a sample of pyrolusite is
Therefore, the weight percent of MnO2 in a sample of pyrolusite is
Category: Chemical Engineering Math
"Published in Vacaville, California, USA"
Calculate the percentage of MnO2 in a 500 mg sample which after the addition of 80.00 mL of 0.1056 M FeSO4 solution required 8.50 mL of 0.0867 M K2Cr2O7?
Solution:
The given word problem is about oxidation reduction reaction or redox in short. A given sample consists of the mixture of impurities and MnO2. FeSO4 solution is used to titrate MnO2 sample and K2Cr2O7 is used for back up titration. Sulfuric acid is added as a catalyst as follows
For back up titration, K2Cr2O7 solution is used to titrate excess FeSO4 solution as follows
The amount of FeSO4 used to titrate MnO2 is
Hence, the weight of MnO2 in a sample is
Therefore, the weight percent of MnO2 in a sample is
