Exams › JEE Main › Chemistry

Which of the following statements is not correct about rusting of iron? (1) Dissolved acidic oxides SO2, NO2 in water act as catalyst in the process of rusting. (2) Rusting of iron is envisaged as setting up of electrochemical cell on the surface of iron object. (3) When pH lies above 9 or 10, rusting of iron does not take place. (4) Coating of iron surface by tin prevents rusting, even if the tin coating is peeling off.

1. Dissolved acidic oxides SO2, NO2 in water act as catalyst in the process of rusting.
2. Rusting of iron is envisaged as setting up of electrochemical cell on the surface of iron object.
3. When pH lies above 9 or 10, rusting of iron does not take place.
4. Coating of iron surface by tin prevents rusting, even if the tin coating is peeling off.

Correct answer: Coating of iron surface by tin prevents rusting, even if the tin coating is peeling off.

Solution

The statement about tin coating is incorrect because if the tin coating peels off, the exposed iron can still rust, as the protective barrier is compromised.

Related JEE Main Chemistry questions

• What volume of 20-volume hydrogen peroxide is needed to produce 5 L of oxygen gas at STP?
• In acidic solution, how many moles of KMnO₄ are needed to oxidize 1 mole of Fe(C₂O₄)₃?
• 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 M^n+ + ne− ⇌ M is highly negative acts as a strong reducing agent. (ii) The oxidizing strength of the halogens decreases in the order chlorine to iodine. (iii) The reducing strength of hydrogen halides increases from hydrogen chloride to hydrogen iodide.
• For the balanced redox equation X MnO4− + Y C2O4^2− + Z H+ → X Mn^2+ + 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

⚔️ Practice JEE Main Chemistry free + battle 1v1 →