What substance turns litmus paper red?
When white paper is impregnated with an alcohol solution of alkannet, it becomes red. This paper is turned to blue shade by alkalis. Litmus paper is used in laboratories to detect the presence of acids and bases (alkalis). Acids turn blue litmus paper red, while bases turn red litmus blue. Neutral solutions (neither base nor acid) do not change its color. A common laboratory practice is to dip pieces of litmus paper into solutions to detect if they are acidic, basic or neutral in nature. Do you know what this litmus paper is? Litmus is a natural dye made from small plants called, “lichens”. These plants are of several varieties and grow in abundance in the Netherlands. When lichen called Rocella Tincotoria is allowed to react with ammonia, potassium carbonate and lime it gives a blue-color material, which is used as the coloring matter for paper. The paper is dipped into it and dried. This is what is known as blue litmus paper and used to test acids. Orchil or cudbear is a red dye obta
