acid-base indicator

Definitions of acid-base indicator

1. noun

   an indicator that changes color on going from acidic to basic solutions
   types:

   phenolphthalein

   a laxative used in many preparations under various trade names; also used as an acid-base indicator in titrations involving weak acids and strong bases because it is brilliant red at high alkalinity and colorless below pH 8

   congo red

   a red-brown azo dye especially as a chemical pH indicator (congo red is red in basic and blue in acidic solutions)

   methyl orange

   an azo dye used as an acid-base indicator; used for titrations involving weak bases

   litmus

   a coloring material (obtained from lichens) that turns red in acid solutions and blue in alkaline solutions; used as a very rough acid-base indicator

   bromophenol blue, bromphenol blue, tetrabromo-phenolsulfonephthalein

   a dye used as an acid-base indicator

   bromothymol blue, bromthymol blue

   a dye used as an acid-base indicator

   type of:

   indicator

   (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction