Question

give scientific reason for following :
It take time for pieces of shahabad tile to disappear in HCL,but it's power disappears rapidly.

Answer 1

Shahabad tiles are made of limestone, which is nothing more than calcium carbonate. Hydrochloric acid dissolves calcium carbonate, but as a powder it has hugely more surface area for the acid to attack than a tile, thus dissolves far faster in powder form than in a solid tile form.