NECTA Form 1–4 (CSEE) · Form 3 · Chemistry (Form 3) · Notes · Unit 4: Hardness of Water, Chemical Causes & Softening Techniques

Unit 4: Hardness of Water, Chemical Causes & Softening Techniques

Official NECTA CSEE Form 3 Chemistry Subtopic 3.3: Definition of hard and soft water, multivalent cations (Ca2+, Mg2+), soap chemistry and scum formation versus synthetic detergents, temporary vs permanent hardness, geological dissolution of limestone, softening temporary hardness (boiling, Clark's slaked lime process), softening permanent hardness (washing soda, ion-exchange zeolite permutit resin and brine regeneration), advantages and disadvantages of hard water, geological cave chemistry (stalactites and stalagmites in Amboni caves), and quantitative EDTA complexometric titrations.