Waste gases are passed through..

[yousawinner]

waste gases cntaining sulphur dioxide are passed through a mixture of water and calcium carbonate 2 remove the sulphur dioxide.explain the action in water and CaCO3.

 

[Miss_Z]

CaCO3 reacts with SO2 to form CaSO3, which is then oxidised by atmospheric O2 to CaSO4 (which can be used for other purposes). Hence SO2, which is a harmful gas, is removed from the waste gases. The process is called 'desulfurisation of flue gases'.