4. A drinking water treatment plant produces water that has an alkalinity of 0.8 meq/L and pH 6.9.To comply with corrosivity rules, the pH must be raised to 8.0 and alkalinity to 2.0 meq/L. To do this a mixture of NaHCO3 and either KOH or HCl is to be added. The Deffeyes diagram may be helpful. а.How much sodium bicarbonate must be added? b. How much either HCl or KOH must be added?

Fig: 1

Fig: 2

Fig: 3