Answer Happy

Reference:
Following the previous question, how much lime and soda (mg/L as CaCO3) are required to completely remove 50 mg/L (as CaCO3) magnesium non-carbonate hardness? Lime: 50; Soda: 50 Lime: 100; Soda: 0 Lime:0; Soda: 50 Lime: 50; Soda: 100
Below is a summary of chemical reactions that occur in lime-soda softening. Unit Operation To add Chemical reaction Equation SI Lime CO₂+ Ca(OH)2 → CaCO3+H₂O Remove CO₂ Remove Ca Lime Ca²+ + 2HCO + Ca(OH)2 → 2CaCO3 + 2H₂O S2 carbonate hardness Remove Mg Lime S3 carbonate hardness Mg²+ 2HCO + 2Ca(OH)2 → 2CaCO₁+Mg(OH)₂ + 2H₂O Remove Ca non- Soda Ca²+SO+NagCO3 CaCO3+2Na+ + S4 carbonate hardness SO4 Remove Mg non- Lime Mg + SO² + Ca(OH)2 → S5a carbonate hardness Mg(OH)2+Ca²+ SO4²- Soda Ca²+ + SO² + NaCO3 → CaCO34+2Na+ + S5b SO Recarbonation CO₂ Ca²+2C0- + 2OH- Ca²+ + 2HCO S6 How much lime (mg/L as CaCO3) is required to remove 50 mg/L (as CaCO3) magnesium carbonate hardness? O100 197 50