Exams › JEE Main › Chemistry

Which of the following equations shows the oxidizing action of H2SO4?

1. 2PCl5 + H2SO4 → 2POCl3 + 2HCl + SO2Cl2
2. 2NaOH + H2SO4 → Na2SO4 + H2O
3. NaCl + H2SO4 → NaHSO4 + HCl
4. 2HI + H2SO4 → I2 + SO2 + 2H2O

Correct answer: 2HI + H2SO4 → I2 + SO2 + 2H2O

Solution

In 2HI + H2SO4 -> I2 + SO2 + 2H2O sulfur is reduced (+6 to +4) while I- is oxidised, so H2SO4 acts as the oxidiser (option 3). The stored NaCl reaction involves no change in oxidation state.

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 →