n-factor for oxidants and reductants, normality

37 questions on n-factor for oxidants and reductants, normality from the Equivalent Concept and Titration chapter: 10 NEET level, 17 JEE Main, 10 JEE Advanced. Each one opens with its answer and solution.

• The n-factor of KMnO4 when it acts as an oxidant in strongly acidic medium (MnO4- -> Mn^2+) is: NEET level
• The n-factor of K2Cr2O7 in acidic medium, where it is reduced to Cr^3+, is: NEET level
• The equivalent mass of FeSO4 (molar mass 152 g mol^-1) when it is oxidised to Fe2(SO4)3 is: NEET level
• Anhydrous oxalic acid H2C2O4 (molar mass 90 g mol^-1) is oxidised to CO2 by KMnO4. Its equivalent mass is: NEET level
• The equivalent masses of KMnO4 (molar mass 158 g mol^-1) as an oxidant in acidic, neutral and strongly alkaline medium respectively are: JEE Main level
• 3.95 g of KMnO4 (molar mass 158 g mol^-1) is dissolved in water to make 250 mL of solution. Select the correct statement(s). JEE Main level
• The strength of a H2O2 solution is 20 volume, i.e. 1 mL of the solution gives 20 mL of O2 at STP on decomposition (2H2O2 -> 2H2O + O2; molar volume 22.4 L at ST... JEE Main level
• FeC2O4 (molar mass 144 g mol^-1) is oxidised completely by acidified KMnO4 to Fe^3+ and CO2. Its equivalent mass is: JEE Main level
• Select the correct n-factor(s) per formula unit of the species named, for the stated change. JEE Main level
• 20.0 mL of 0.100 M FeSO4 is titrated in acidic medium with 0.0200 M K2Cr2O7 (Cr2O7^2- -> Cr^3+). The volume of dichromate needed is: JEE Main level
• Mohr's salt, FeSO4.(NH4)2SO4.6H2O, is titrated with acidified KMnO4. Using Fe=56, S=32, N=14, O=16, H=1, its equivalent mass is: JEE Main level
• Bromine disproportionates in hot alkali: 3Br2 + 6OH- -> 5Br- + BrO3- + 3H2O (Br=80). The equivalent mass of Br2 in this reaction is: JEE Advanced level
• Cu2S (Cu=63.5, S=32) is oxidised by acidified KMnO4 to Cu^2+ and SO2. Calculate the mass of KMnO4 (molar mass 158 g mol^-1) required to oxidise 0.795 g of Cu2S,... JEE Advanced level
• 0.690 g of pure K2Cr2O7 (molar mass 294 g mol^-1) is treated with excess acidified KI, liberating I2 (dichromate goes to Cr^3+). The iodine is titrated with 0.0... JEE Advanced level
• An acidified solution contains 3.00x10^-3 mol FeSO4 and 1.20x10^-3 mol Fe2(C2O4)3. It is titrated with 0.0250 M KMnO4 (acidic medium). Only Fe^2+ and oxalate ar... JEE Advanced level
• Sodium thiosulfate (Na2S2O3, molar mass 158 g mol^-1; Na2S2O3.5H2O=248 g mol^-1) is oxidised by I2 to tetrathionate, and by excess Cl2 water to sulfate (S2O3^2-... JEE Advanced level
• Fe3O4 (molar mass 232 g mol^-1) is (i) oxidised completely to Fe2O3 by KMnO4 and (ii) reduced completely to Fe by hydrogen. The equivalent masses of Fe3O4 in (i... JEE Advanced level
• 1.89 g of oxalic acid dihydrate H2C2O4.2H2O (molar mass 126 g mol^-1) is titrated in hot acidic medium with 0.040 M KMnO4. Select the correct statement(s). JEE Main level
• In strongly acidic medium KMnO4 (molar mass 158 g mol^-1) is reduced to Mn^2+. Its equivalent mass is: NEET level
• When oxalic acid, H2C2O4, is oxidised completely to CO2 by acidified permanganate, its n-factor is: NEET level
• Ferrous oxalate, FeC2O4, is oxidised by acidified KMnO4 to Fe^3+ and CO2. The n-factor of FeC2O4 is: NEET level
• A 0.20 M solution of H3PO4 is completely neutralised to Na3PO4 by NaOH. Its normality is: NEET level
• The molar mass of K2Cr2O7 is 294 g mol^-1. Its equivalent mass when it oxidises in acidic medium (to Cr^3+) is: NEET level
• Thiosulphate is oxidised by iodine as 2S2O3^2- + I2 -> S4O6^2- + 2I-. Taking the molar mass of Na2S2O3 as 158 g mol^-1, its equivalent mass in this reaction is: NEET level
• 6.3 g of oxalic acid dihydrate, H2C2O4.2H2O (molar mass 126 g mol^-1), is dissolved in water to make 500 mL of solution. Its normality when used as a reducing a... JEE Main level
• The ratio of the equivalent mass of KMnO4 in strongly acidic medium (reduced to Mn^2+) to its equivalent mass in neutral medium (reduced to MnO2) is: JEE Main level
• 27.5 mL of 0.0360 M KMnO4 in acidic medium is exactly equivalent to what volume (in mL) of 0.0850 M oxalic acid (H2C2O4, oxidised to CO2)? Give the answer to on... JEE Main level
• Which of the following statements about n-factors is/are correct? JEE Main level
• In hot concentrated alkali iodine disproportionates: 3I2 + 6OH- -> 5I- + IO3- + 3H2O. The n-factor of I2 in this reaction is: JEE Main level
• A '20 volume' H2O2 solution gives 20 mL of O2 at STP per mL of solution on decomposition (molar volume 22.4 L mol^-1). Its normality, taking n-factor of H2O2 as... JEE Main level
• 150 mL of 0.12 M H2SO4 is mixed with 350 mL of 0.10 M HCl. Find the normality of the resulting solution as an acid (two decimals). JEE Main level
• Which of the following are correct for 0.1 M solutions of the given substances? (Na2CO3 is titrated with a strong acid using phenolphthalein, i.e. only up to Na... JEE Main level
• Mohr's salt, FeSO4.(NH4)2SO4.6H2O, is used as a reductant (Fe^2+ -> Fe^3+). Using Fe=56, N=14, S=32, O=16, H=1, find the mass (in g, two decimals) required to p... JEE Main level
• Acidified KMnO4 oxidises Cu2S to Cu^2+ and SO2 (the manganese ends as Mn^2+). The number of moles of KMnO4 consumed per mole of Cu2S is: JEE Advanced level
• Acidified KMnO4 (36.0 mL of 0.0500 M) just oxidises a sample of Cu2S to Cu^2+ and SO2. Using Cu=63.5 and S=32, find the mass of Cu2S in the sample, in mg to the... JEE Advanced level
• Ferrous oxalate, FeC2O4 (molar mass 144 g mol^-1), is completely oxidised by acidified KMnO4 to Fe^3+ and CO2. Which statements are correct? JEE Advanced level
• White phosphorus disproportionates in alkali: P4 + 3NaOH + 3H2O -> PH3 + 3NaH2PO2. Taking the molar mass of P4 as 124 g mol^-1, find the mass (in g, two decimal... JEE Advanced level