500 mL of 0.2 M MnO4- solution in basic medium when mixed with 500 mL of 1.5 M KI solution, oxidises iodide ions to liberate molecular iodine. This liberated iodine is then titrated with a standard x M thiosulphate solution in presence of starch till the end point. If 300 mL of thiosulphate was consumed, then the value of x is .
Redox Reactions
Previous year questions with solutions · 2025 – 2026
Year-wise statistics questions · papers · average per paper · weightage
| Year | Questions | Papers | Avg / paper | Weightage |
|---|---|---|---|---|
| 2026 | 6 | 19 | 0.32 | 1.26% ↑278.9% |
| 2025 | 1 | 12 | 0.083 | 0.33% |
In order to oxidise a mixture of 1 mole each of FeC2O4, Fe2(C2O4)3, FeSO4 and Fe2(SO4)3 in acidic medium, the number of moles of KMnO4 required is
- 3
- 2
- 5
- 7
Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
500 mL of 1.2 M KI solution is mixed with 500 mL of 0.2 M KMnO4 solution in basic medium. The liberated iodine was titrated with standard 0.1 M Na2S2O3 solution in the presence of starch indicator till the blue color disappeared. The volume (in L) of Na2S2O3 consumed is . (Nearest integer)
X and Y are the number of electrons involved, respectively during the oxidation of I- to I2 and S2- to S by acidified K2Cr2O7. The value of X + Y is .
200 cc of x 10-3 M potassium dichromate is required to oxidise 750 cc of 0.6 M Mohr's salt solution in acidic medium. Here x = .
Match the List-I with List-II Choose the correct answer from the options given below:
- A-III, B-IV, C-I, D-II
- A-IV, B-I, C-II, D-III
- A-II, B-III, C-I, D-IV
- A-II, B-III, C-IV, D-I