Universal Indicator

[David W Walker]

Peter Kubotani <kubotani at wimsey.com> wrote:
>Does anyone know what is the composition of a universal indicator?

There are a range available. Merck for example have one for a pH range 
from 1-14 and another 4-11. The former they call the Full Range 
Indicator and the latter a Universal Indicator in their catalogue.

The components of the latter are typically:
methyl red 
alpha-naphtholphthalein
thymolphthalein
phenolphthalein
bromothymol blue

Not sure of the composition of each component, but it's not worth 
making it up because it's widely available in solution or as test papers.

Dave Walker
 


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 David W Walker    EMail dave at diwalk.demon.co.uk                            
                                        
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