Question

Give reasons : Iron sheets are cleaned with hydrochloric acid before dipping into molten zinc for galvanizing.

Answer 1

When iron sheets are washed with HCl, It reacts with the various impurities such as,

Fe2O3+4HCl→ FeCl2+H2O+O2

Fe(OH)2+2HCl→FeCl2+2H2O

If they were not removed, the would probably compromise the Zinc protection as they would react with the zinc from the inside and damage the zinc protection.