The iron carbide studies, made with Carapella's reagent (5 gm. ferric chloride, 2 ml. concentrated hydrochloric acid and 99 ml. methyl alcohol) etching for 20–60 min., revealed cracking as the ...

Wear safety goggles and latex gloves to protect the eyes and hands from the strong acid and base used in this demonstration. Keep the containers of concentrated hydrochloric acid and aqueous ammonia ...