What is noticed when permanent hard water is treated with - slaked?
MgSO4 is soluble in water. When Ca (OH)2 is added to water it reacts to form Mg(OH)2 which is insoluble and precipitates out. CaCl2 is soluble in water. When Na2CO3 is added to water, it reacts with Cacl2 to form CaCO3 and 2NaCl.