Name this common indicator that is red for acids and blue for bases.
This material is extracted from lichens. It typically is added to filter paper or wood pulp that has been treated with solvents. Because lichens are made of two different living organisms, they can change based on whether they are in an environment that favors one organism or the other. This particular substance can differentiate well between, for example, bleach and lemon juice. Name this common indicator that is red for acids and blue for bases.
This material is extracted from lichens. It typically is added to filter paper or wood pulp that has been treated with solvents.
Litmus (Paper) (prompt Indicator)