12. Collect a sample of lake water; a) 100 mL titrate with 0.05N HCl to HCO3' eq.pt. and we need to add 0.5 mL of acid solution. What is the CO32- ALK as M and mg CaCO3/L? b) 100 mL titrate with 0.03N NaOH to CO3- eq.pt. and we need to add 0.6 mL of base solution. What is the OH'ALK as M and mg CaCO3/L? c) What is the Ct and pH value