Redox Reactions as the Basis for Titrations

Author:Dr. S.N. DHAWAN, Dr. S.C.KHETERPAL & P.N.KAPIL
11th CBSE
IMPORTANT

Important Questions on Redox Reactions as the Basis for Titrations

HARD
IMPORTANT

How many grams of potassium dichromate are required to oxidise 20.0 g of Fe2+ in FeSO4 to Fe3+ if the reaction is carried out in an acidic medium ? (Molar mass of K2Cr2O7 and FeSO4 are 294 and 152 respectively)

Round off your answer to the nearest integer.

EASY
IMPORTANT

Reaction of Br2 with Na2CO3 in aqueous solution gives sodium bromide and sodium bromate with evolution of CO2 gas. The number of sodium bromide molecules involved in the balanced chemical equation is 

EASY
IMPORTANT

How many moles of iodine are liberated when 2 moles of potassium permanganate react with potassium iodide?

MEDIUM
IMPORTANT

Ceric ammonium sulphate and potassium permanganate are used as oxidising agents in acidic medium for oxidation of ferrous ammonium sulphate to ferric sulphate. The ratio of number of moles of cerium ammonium sulphate required per mole of ferrous ammonium sulphate to the number of moles of KMnO4 required per mole of ferrous ammonium sulphate is

MEDIUM
IMPORTANT

MnO4- ions are reduced in acidic condition to Mn2+ions whereas they are reduced in neutral condition to MnO2. The oxidation of 25 mL of a solution X containing Fe2+ ions required in acidic condition 20 mL of a solution Y containing MnO4- ions. What volume of solution Y would be required to oxidise 25 mL of solution X containing Fe2+ ions in neutral condition? 

MEDIUM
IMPORTANT

3.92 g of ferrous ammonium sulphate are dissolved in 100 mL water. 20 mL of this solution requires 18 mL of potassium permanganate during the titration for complete oxidation. The weight of KMnO4 present in one litre of the solution is (acidic medium)

EASY
IMPORTANT

How many mL of 0.125 M Cr3+ must be reacted with 12.00 mL of 0.200 M MnO4- if the redox products are Cr2O72-and Mn2+?

HARD
IMPORTANT

Assuming complete ionization, the same moles of the following compounds will require the least amount of acidified KMnO4 for complete oxidation? 

EASY
IMPORTANT

Number of moles of MnO4- required to oxidize one mole of ferrous oxalate completely in acidic medium will be

EASY
IMPORTANT

Consider the titration of potassium dichromate solution with acidified Mohr's salt solution using diethylamine as indicator. The number of moles of Mohr's salt required per mole of dichromate is 

EASY
IMPORTANT

The number of moles of KMnO4 needed to react with one mole of SO32- in acidic solution is

EASY
IMPORTANT

The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is

EASY
IMPORTANT

For decolourization of 1 mole of KMnO4, the moles of H2O2 required is

EASY
IMPORTANT

KMnO4 acts as an oxidising agent in alkaline medium. When alkaline KMnO4 is treated with KI, iodide ion is oxidised to

EASY
IMPORTANT

Discuss briefly the function of the salt bridge in an electrochemical cell.

HARD
IMPORTANT

Draw a labelled diagram for the Daniel cell. Discuss its working.

HARD
IMPORTANT

Both Cr2O72 (aq) and MnO4(aq) can be used to titrate Fe2+(aq). If in a given titration, 24.50 cm3 of 0.1 M Cr2O72 were used, than what volume of 0.1 M MnO4 solution would have been used for the same titration?

MEDIUM
IMPORTANT

50 mL of an aqueous solution of H2O2 was reacted with excess of KI solution and dilute H2SO4. The liberated iodine required 20 mL 0.1 N Na2S2O3 solution of complete interaction. Calculate the concentration of H2O2 in gL1.

MEDIUM
IMPORTANT

2.48 g of Na2S2O3.xH2O was dissolved per litre of the solution. 20 mL of this solution required 10 mL, 0.01 M iodine solution. Find out the value of x.

MEDIUM
IMPORTANT

How many millimoles of potassium dichromate is required to oxidise 24 mL of 0.5 M  Mohr's salt solution in acidic medium?