[Euclid]

How would CO2 absorbed from the atmosphere affect the molarity of a solution? Would it be associated with water vapour and result in a lower molarity? Hmm... Thanks

[Yggdrasil]

CO₂ will affect the normality for an acid or base solution because when CO₂ disolves in water it forms an acid which will alter the pH of the solution (and hence the concentrations of H⁺ and OH^-):

CO₂ + H₂O <--> H₂CO₃ <--> H⁺ + HCO₃^- <--> 2H⁺ + CO₃^2-