Which ferric salt is listed as a miscellaneous corrosive chemical?

• A. Calcium carbonate
• B. Sodium chloride
• C. Potassium iodide
• D. Ferric chloride

Answer: (D)

Understanding what makes a chemical a corrosive helps you classify it correctly. A corrosive substance can damage skin, eyes, and metals on contact, and some chemicals sit in a general “miscellaneous corrosives” category because they don’t fit neatly into the main acid or base groups.

Ferric chloride (FeCl3) is a strong corrosive salt. In solution it behaves aggressively toward skin and eyes and can corrode metals, so it belongs in the miscellaneous corrosive category on many safety lists. The other options are not corrosive: calcium carbonate is a common, mild salt often used as a filler or antacid; sodium chloride is table salt and is essentially non-corrosive; potassium iodide is another relatively stable salt. Thus ferric chloride is the one that fits the miscellaneous corrosive designation.