General Science question from FAA exam, 2024 by JKSSB
Food cans are coated with tin instead of zinc due to
Last updated May 13, 2026
Correct Answer:
Option B —
Zinc is more reactive than tin.
1. The Reactivity Factor Zinc is positioned higher than tin in the reactivity series. This means zinc reacts much more readily with substances, especially the organic acids naturally found in food (like citric acid in fruits or acetic acid in pickles).If food were stored in zinc-coated cans, the metal would react with the food to form toxic compounds. Tin, being less reactive, does not react with food acids under normal conditions, keeping the contents safe for consumption.
2. The Protective Barrier Tin coating acts as a non-reactive barrier. Even though tin is more expensive than zinc, it is used because it provides corrosion resistance without leaching harmful chemicals into the meal.
3. Analyzing the Other Options
A) Zinc is costlier than tin: This is actually false; tin is generally more expensive than zinc. However, safety (reactivity) is the primary reason for the choice, not cost.
C) Zinc has a higher melting point: While true for Zinc vs for Tin), the melting point isn't the concern for room-temperature food storage; chemical stability is.
D) Zinc is less reactive than tin: This is scientifically incorrect.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
