A groundwater source entering a drinking water treatment plant was measured to have a pH = 7.8 and an alkalinity of 76 mg/L as CaCO3. The water is not initially equilibrated with the atmosphere. (a) Calculate the concentration of H2CO3*, HCO3-, and CO32- in the water (in units of mole/L). (b) Determine the alkalinity and pH of the water from part (a) after 5x10-4 M HCl, a strong acid that completely dissociates to H+ and Cl- when added to water, is added and allowed to equilibrate. Assume that the re-equilibration is rapid and total dissolved carbonate (CT,CO3) remains unchanged.