My teacher said that we always used indicators such as methyl red, methyl orange, litmus, phenolphthalein, etc. rather than universal indicator. I don't understand why, though, would not universal indicator serve the same function, but for essentially all titrations rather than select few?


2 Answers 2


The thing with universal indicators is that you have 6 different colors or so differentiating certain pH-ranges.

Now if you want to titrate to a certain pH-Value, it is easier to have an indicator like phenolphtalein that changes from colorless to a color at a certain point (phenolphtalein being colorless from 0 to 8 and red for $< 0$).

So you can titrate more accuratly to a certain pH-Value with specialized indicators. On the other hand you can't see where on the pH scale you are.

With an universal indicator you can get a feeling for where you are approximatly, but titrating to a certain value is very difficult.


I'm a chemistry teacher. I quite like using universal indicator. It usually goes from red/orange to yellow in one drop, then to green in another drop, then to blue/purple after another drop. We stop at green (neutral). I like it because it's clearly green.

With phenolphthalein we stop when the pale pink persists for approx 30 seconds, but students usually aren't satisfied this and go past the end point by making sure the solutions remains pink by which point it's probably gone past neutral.


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