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
Dissociation (chemistry) variously named a "dissociation constant", an "acid ionization constant", an "acidity constant" or an "ionization constant". It serves as an indicator of the acid strength: stronger acids have a higher "K" value (and a lower p"K" value). Fragmentation of a molecule can take place by a process of heterolysis or homolysis. Receptors are proteins that bind small ligands. The dissociation constant "K" is used as indicator of the affinity of the ligand to the receptor. The higher the affinity of the ligand for the receptor the lower the "K" value (and the higher the p"K" value). Dissociation (chemistry) Dissociation in