Question

What is hard and soft water and removal of hardness of water by different methods for project work of 3 to 5 pages

Answer 1

hard water :-hard water forms precitation with soap . which is not suitable for laundry.
soft water:-just opposite nature of hard water this is suitable for laundry. and nn forms precipitation with soap.
the hardness of water removed through following method.
1) boiling :-if we boiled hard water Mg (HCO3)2 is precipitated as Mg (OH)2 whereas Ca (HCO3) 2 is precipitated as CaCO3.
2) clark method :-required amount of lime is added to hard water that precipitates hydrogen carbonate .
Ca (HCO3) 2+Ca (OH) 2--> CaCO3+H2O
3) calgan method:-sodium hexametaphosphate is added to hard water rhat remove chloride and sulphate. 4) ion exchange method :-hydrated sodium aluminum silicate is added to hard water that removes hardness through ions exchange reaction.
2NaAlSiO4 (s) +M+(aq)----> M (AlSiO4)(s) 2+2Na+(aq)
5) treatment with Na2CO3:-if we treat hard with Na2CO3 . chloride and sulphate remove .
MCl2+Na2CO3-----> MCO3 (s)+2NaCl