5. Although the measures of lockdown in some countries during the epidemic period
have caused reduction in some air pollutants, the concentration of carbon dioxide
(CO2) in the atmosphere have still been rising. Now, the concentration of CO2 is
420 ppm at I atm in the atmosphere. When the rainwater and the air are completely
balanced, the rainwater will infiltrate into the layer of groundwater in the catchment
area, where it contains calcium carbonate (CaCO3).
【題組】(c)What is the pH of rainwater when it has balanced with CaCO3 in the layer of
groundwater? (5 pts)