1
IIT-JEE 1991
Subjective
+4
-0
A 1.0 g sample of Fe2O3 solid of 55.2% purity is dissolved in acid and reduced by heating the solution with zinc dust. The resultant solution is cooled and made upto 100.0 ml. An aliquot of 25.0 ml of this solution requires 17.0 ml of 0.0167M solution of an oxidant for titration. Calculate the number of electrons taken by the oxidant in the reaction of the above titration.
2
IIT-JEE 1991
Subjective
+5
-0
A solution of 0.2 g of a compound containing Cu2+ and $$C_2O_4^{2-}$$ ions on titration with 0.02M $$KMnO_4$$ in presence of $$H_2SO_4$$ consumes 22.6 ml. of the oxidant. The resultant solution in neutralized with Na2CO3, acidified with dil. acetic acid and treated with excess KI. The liberated iodine requires 11.3 ml of 0.05M Na2S2O3 solution for complete reduction.

Find out the molar ratio of Cu2+ to $$C_2O_4^{2-}$$ in the compound.Write down the balanced redox reactions involved in the above titrations.
3
IIT-JEE 1990
Subjective
+5
-0
A mixture of H2C2O4 (oxalic acid) and NaHC2O4 weighing 2.02 g was dissolved in water and solution made upto one litre. Ten millilitres of the solution required 3.0 ml. of 0.1 N sodium hydroxide solution for complete neutralization. In another experiment, 10.0 ml. of the same solution, in hot dilute sulphuric acid medium. require 4.0 ml. of 0.1 N potassium permanganate solution for complete reaction. Calculate the amount of H2C2O4 and NaHC2O4 in the mixture.
4
IIT-JEE 1990
Subjective
+4
-0
A solid mixture (5.0 g) consisting of lead nitrate and sodium nitrate was headed below 600oC until the weight of the residue was constant. If the loss in weight 28.0 percent, find the amount of lead nitrate and sodium nitrate in the mixture.
EXAM MAP
Medical
NEET