A universal indicator is a blend of pH indicator solutions designed to
identify pH of a solution over a wide range of values. There are several
different formulas for universal indicators, but most are based on a
patented formula developed in 1933 by Yamada. A common mixture includes
thymol blue, methyl red, bromothymol blue, and phenolphthalein.

Color change is used to identify pH values. The most common universal indicator colors are:

Red 0 ≥ pH ≥ 3

Yellow 3 ≥ pH ≥ 6

Green pH = 7

Blue 8 ≥ pH ≥ 11

Purple 11 ≥ pH ≥ 14

However, the colors are specific to the formulation. A commercial
preparation comes with a color chart that explains the expected colors
and pH ranges.

While a universal indicator solution may be used to test any sample, it
works best on a clear solution because it's easier to see and interpret
the color change.


Geezgo for free. Use Geezgo's end-to-end encrypted Chat with your
Closenets (friends, relatives, colleague etc) in personalized ways.

Post a Comment

Previous Post Next Post