Which metal can be used as a sacrificial anode to protect an iron pipe from corrosion?

• A. Gold
• B. Zinc
• C. Copper
• D. Silver

Answer: (B)

Verified step by step guidance

1. Understand the concept of a sacrificial anode: it is a more reactive metal that corrodes (oxidizes) preferentially to protect another metal, such as iron, from corrosion.
2. Recall the activity series of metals, which ranks metals by their tendency to lose electrons and oxidize. Metals higher in the series are more reactive and will corrode before metals lower in the series.
3. Identify iron's position in the activity series. Iron is moderately reactive, so the sacrificial anode must be a metal more reactive than iron.
4. Compare the given metals (Gold, Zinc, Copper, Silver) to iron in the activity series. Zinc is more reactive than iron, while gold, copper, and silver are less reactive.
5. Conclude that zinc can be used as a sacrificial anode because it will oxidize first, protecting the iron pipe from corrosion.