Question

In which of the following reactions, we observe the unaffected corrosion rate with the increase in temperature?

(a) 18Cr-8Ni in HNO3

(b) 18Cr-8Ni in H2SO4

(c) Ni in HCl

(d) Fe in HF

Answer 1

The correct choice is (a) 18Cr–8Ni in HNO3

For explanation I would say: Stainless steel (18Cr–8Ni) in the HNO3 medium will have a negligible effect on the corrosion rate with the increase in temperature. It forms a stable oxide layer and avoids the exposure of a corrosive atmosphere to the metallic surface. It is stable up to very high temperatures.