Q23
1 markMCQSection B

Galvanization is a process of coating iron articles with a thin layer of zinc to prevent iron from rusting. The iron is protected even if the zinc coating is scratched and iron is exposed. Which of the following is/are true about how zinc prevents the rusting of iron?

(P) A galvanised iron article does not undergo oxidation.

(Q) The zinc coating prevents contact of iron with air.

(R) Zinc provides continuous protection to iron from rusting.

Chemical Reactions and Equations
Corrosion and Prevention

Options

(A)Only (P)
(B)Only (Q)
(C)(Q) and (R)
(D)(P) and (Q)
Official Answer

Option C is correct: (Q) and (R) are true.

GalvanizationZinc coatingOxidationSacrificial protectionBarrier

Marking Scheme

  • 11 mark for selecting the option that correctly identifies the barrier and sacrificial roles of zinc.

Hint

Think about whether the zinc layer acts only as a barrier or if it reacts itself.

Quick Oral Answer

Zinc prevents rusting by acting as a physical barrier and by providing sacrificial protection, where zinc oxidizes instead of the iron.

Analysis & Explanation

Statement (P) is false because the zinc coating itself undergoes oxidation to protect the iron; this is known as sacrificial protection. Statement (Q) is true because the zinc layer acts as a physical barrier, preventing the iron from coming into contact with moisture and oxygen in the air. Statement (R) is true because even if the coating is scratched, the remaining zinc continues to react preferentially over the iron, providing continuous protection.

Common Mistakes

  1. 1Thinking that galvanization stops all oxidation; it only stops the oxidation of iron.
  2. 2Believing protection stops once the coating is scratched.

Interesting Facts

Zinc is more reactive than iron, which is why it oxidizes first, 'sacrificing' itself to save the iron.

Spotted a mistake or something unclear?

Tell us — we fix reported answers fast.

Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2026?

This question carries 1 mark in the CBSE Class 10 Science 2026 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Chemical Reactions and Equations" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Corrosion and Prevention" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2026 paper?

This is a MCQ question from Section B in the CBSE Class 10 Science 2026 paper.