As an engineer working with the Water Supplies Department, you have recently discovered an isolated aquifer with groundwater. The groundwater has a temperature of 20C, contains 5108 mol/L hydrogen ions ([H+])and alkalinity (ALK) of 100mg/L as CaCO3, answer the following questions: (a) Find the pH of the groundwater (round your answer to 1 decimal place). (1 mark) (b) Express alkalinity in unit of meq/L. (2 marks) (c) Bicarbonate concentration ([HCO3])can be used as an approximation of the groundwater's alkalinity. Explain the reasons behind this approximation and calculate the molar concentration of bicarbonate. (9 marks) (d) Find the concentration of carbonic acid ([H2CO3]) and the partial pressure of CO2(PCO2) that is in equilibrium with the groundwater. (4 marks) (e) Compare the PCO2 in confined aquifer with the atmospheric PCO2 and describe what will happen when the groundwater is exposed to the atmosphere (2 marks)