Marble chips,`CaCO_(3)`, on reaction with `H_(2)SO_(4)` gives white ppt. of `CaSO_(4)`, which deposit on marble and hence forms a fine layer. Thus, any further reaction between marble chips and `H_(2)SO_(4)` stops.
`CaCO_(3)+H_(2)SO_(4)toCaSO_(4)+CO_(2)+H_(2)O`
