Litmus "Lecanora tartarea" (Norway, Sweden), "Variolaria dealbata", "Ochrolechia parella", "Parmotrema tinctorum", and "Parmelia". Currently, the main sources are "Roccella montagnei" (Mozambique) and "Dendrographa leucophoea" (California). The main use of litmus is to test whether a solution is acidic or basic. Wet litmus paper can also be used to test for water-soluble gases that affect acidity or alkalinity; the gas dissolves in the water and the resulting solution colors the litmus paper. For instance, ammonia gas, which is alkaline, turn the red litmus paper blue. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or
Alkalinity alkalinity of a typical seawater sample. Contributions are in μmolkg−soln and are obtained from "A Handbook of Methods for the analysis of carbon dioxide parameters in seawater "","(Salinity = 35 g/kg, pH = 8.1, Temperature = 25 °C). Phosphates and silicate, being nutrients, are typically negligible. At pH = 8.1 [HSO] and [HF] are also negligible. So, Addition (or removal) of CO to a solution does not change its alkalinity, since the net reaction produces the same number of equivalents of positively contributing species (H) as negative contributing species (HCO and/or CO). Adding CO to the solution lowers its pH,