Question

Which of the following material is/are primarily used for hydrofluoric acid?

(a) High-silicon cast iron

(b) Magnesium

(c) Aluminum

(d) Glass and stoneware

The question was asked by my college director while I was bunking the class.

Question is taken from Mineral Acids in section Mineral Acids of Corrosion Engineering

Answer 1

Correct answer is (b) Magnesium

Easy explanation: Materials such as high-silicon cast iron, aluminum, glass, and stoneware are generally resistant to many acids but these are readily attacked in hydrofluoric acid. Whereas magnesium is practically immune to corrosion because of the formation of a surface fluoride film.