Making universal indicator?

Hi everyone,

I had thought I had enough UI in the bottles but I have just looked and most are near empty!

I was just curious to know if it is possible to make UI solution from the chemicals we have in the preproom?

Thank you x
 
I have found 3/4 of the indicators...

I have a chemical called thymol, but it doesn't say thymol blue? Is this the same chemical?

Thank you x
 

Peter Sigsworth

COMMITTEE
I have found 3/4 of the indicators...

I have a chemical called thymol, but it doesn't say thymol blue? Is this the same chemical?

Thank you x
Test with acid/alkali if it shows the colour change yellow pH 1 then green pH 7 and blue pH 12 then it will do. That's for bromothymol blue.
 

Peter Sigsworth

COMMITTEE
I get no colour change for thymol blue - is this chemical known by another name?
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6.
 
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6.
Yep, definetely not the chemical I have.

Will omitting this (but leaving the other 3) be noticable?

I am testing the pH of HCl, lemon juice, vinegar, detergent & NaOH
 
I did read on another thread that current stock can be diluted to some extent...might have to do until I order more of the one indicator I am lacking.

Seems it can be diluted down 50:50 with water...
 
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