What is the degree of hardness of a sample of water containing 6 mg of MgSO_4 (molecular mass 120) per kg of water ?

What is the degree of hardness of a sample of water containing 6 mg of

1.	What is the degree of hardness of a sample of water containing 6 mg of MgSO_4 (molecular mass 120) per kg of water ?
Answer» Solution :6 mg of `MgSO_4` present in `10^3` g of water `10^6` g water will contain ` =6000 mg` of `MgSO_4` `120 g "of " MgSO_4`= 100 g of `CaCO_3` So, 6g of `MgSO_4 = 100/120 XX 6 = 5G " of " CaCO_3`, i.e., Hardness= 5 PPM `LiH + H_2O to LIOH + H_2`