Answer: The purest form of iron (<0.2% C), malleable and tough.
- A The purest form of iron (<0.2% C), malleable and tough
- B Essentially the same as pig iron, with a similarly high carbon content
- C Identical to cast iron, sharing its characteristic brittleness
- D A modern steel alloy containing significant chromium and nickel
Correct answer: A. The purest form of iron (<0.2% C), malleable and tough
Explanation: Wrought iron is almost pure iron (0.1-0.2% C) made by removing impurities from pig iron; it is malleable, ductile, and resistant to corrosion.
An Ellingham diagram plots ΔG° of oxide formation against temperature for different metals; whichever line is LOWER (more negative ΔG°) at a given temperature reduces the oxide of any metal whose line sits above it - the basis of carbon reduction (Fe, Zn) vs electrolytic reduction (Al, Mg, Na) decisions.
Concept context
The science of extracting metals from ores and refining them for use. Covers concentration methods, reduction techniques, refining processes, and the thermodynamic principles that govern metal extraction.