litmus

views updated May 09 2018

litmus A dye obtained from lichens of the genus Roccella. Litmus is used as a pH indicator, being red under acidic conditions and blue under alkaline conditions.

litmus

views updated May 21 2018

lit·mus / ˈlitməs/ • n. a dye obtained from certain lichens that is red under acid conditions and blue under alkaline conditions.

litmus

views updated May 14 2018

litmus Dye that is purple in neutral aqueous solutions; it is used to indicate acidity (turning red) or alkalinity (turning blue). It is most familiar in the form of litmus paper used as an acid-base indicator. The dye is extracted from lichens. See also pH

litmus

views updated May 21 2018

litmus blue colouring matter from lichens. XVI. — ONorw. litmosi, f. ON. litr dye + mosi MOSS.

litmus

views updated Jun 08 2018

litmus (lit-mŭs) n. a pigment used as an indicator of acids and alkalis. In the presence of acids it turns red; with alkalis it turns blue.