4 SO SO SO HSO 3 H SO H SO SCL H The degree of hardness of

Last updated: 7/2/2023

4 SO SO SO HSO 3 H SO H SO SCL H The degree of hardness of water is usually expressed in terms of 1 g L of CaCO and MgCO present 2 ppm by weight of MgSO 3 ppm of CaCO actually present in water 4 ppm by weight of CaCO irrespective of whether it is actually present