Congo red is a synthetic dye that exhibits acidic properties. It is often used as a pH indicator, changing color from blue in alkaline solutions to red in acidic environments. This characteristic makes it useful in various applications, including biological staining and pH testing.
Basic dyes: Crystal violet, Methylene blue, Malachite green, Safranin. Acidic dyes: Nigrosin, Congo red
Nigrosin
changes to violet in basic solution
Red color in acidic solutions and blue color in basic solutions.
Cyanidin is red in acidic solution, and blue in basic solution
It helps in indicating whether a substance is acidic or basic A red litmus paper turns blue in basic solution and turns red in acidic solution A blue litmus paper turns red in acidic solution and turns darker blue in basic solution
Red color in acidic solutions and blue color in basic solutions.
Red color in acidic solutions and blue color in basic solutions.
Blue Litmus Paper turns red when it is placed in an acid
In acid conditions it is colorless and in basic conditions it is pink and then bright red
Litmus paper is red for acidic solutions and is blue for basic solutions.
Red color in acidic solutions and blue color in basic solutions.