Exams › JEE Main › Chemistry

Excess of KI reacts with CuSO4 solution and then Na2S2O3 is added to it. Which of the statements is incorrect for this reaction ?

1. Na2S2O3 is oxidised
2. CuI2 is formed
3. Cu2I2 is formed
4. Evolved I2 is reduced

Correct answer: CuI2 is formed

Solution

CuI2 is formed because the excess of KI reacts with CuSO4 to produce copper(I) iodide (CuI), and in the presence of excess iodide, it can further react to form CuI2, which is a stable compound in this context.

Related JEE Main Chemistry questions

• What volume of 20-volume hydrogen peroxide is needed to produce 5 L of oxygen gas at STP?
• Which one of the following reactions shows sulfuric acid acting as an oxidizing agent?
• Which of the following statements about redox behavior are true? (i) A metal M whose standard reduction potential for the half-reaction Mⁿ⁺ + ne⁻ ⇌ M is highly negative acts as a strong reducing agent. (ii) The oxidizing strength of the halogens falls in the order chlorine to iodine. (iii) The reducing strength of hydrogen halides rises from hydrogen chloride to hydrogen iodide.
• For the balanced redox equation X MnO4⁻ + Y C2O4²⁻ + Z H⁺ → X Mn²⁺ + 2Y CO2 + Z/2 H2O, what are the values of X, Y, and Z, respectively?
• Balance the redox equation below and identify the coefficients X, Y and Z in order: XNa2HAsO3 + YNaBrO3 + ZHCl → NaBr + H3AsO4 + NaCl
• Arrange the following sulphur-containing anions in order of increasing oxidation state of sulphur: SO3²⁻, S2O4²⁻ and S2O6²⁻.

⚔️ Practice JEE Main Chemistry free + battle 1v1 →