Which of the following statements is not correct about rusting of iron?

Strategy: Rusting is an electrochemical pro\cess. Evaluate the role of coatings, pH, and pollutants based on electrode potential and acid-base chemistry.

Step 1: Evaluate Statement (a) Tin ($E^\circ = -0.14\text{ V}$) is less active than Iron ($E^\circ = -0.44\text{ V}$). If the tin coating is scratched (peeled off), Iron becomes the anode and undergoes sacrificial corrosion even faster than without the tin. Thus, tin only protects iron while the coating is perfectly intact.

Step 2: Evaluate other statements

• (b): In alkaline conditions ($\text{pH} > 9$), the $\ce{H^+}$ concentration is too low for the reduction pro\cess required for rusting. (True)
• (c): Acidic oxides like $\ce{SO2}$ lower the pH, acting as electrolytes and catalysts. (True)
• (d): Rusting is indeed modeled as a tiny galvanic cell on the metal surfa\ce. (True)

$\boxed{\text{Answer: (a)}}$