How to define alkali

How to define alkali

Alkalis easily are defined by means of indicators as which the phenolphthalein and litmus changing the color depending on the pH level of the tested environment can act.

It is required to you

  • Litmus or phenolphthalein


1. If you in existence have litmus in the liquid state, you should add carefully several drops of this substance to a test tube with estimated alkali. If in solution litmus is painted in bright blue color, it will be the proof that before you really alkaline environment. If color of the indicator remains violet, it will mean that Wednesday in a test tube neutral (for example, water). In case litmus is painted in red, it will be an indicator of the acid environment.

2. As the indicator you can also use a litmus piece of paper. You will need to lower accurately its tip in the checked solution. Blue coloring of a piece of paper will prove presence of alkali at a test tube.

3. As the indicator you can also use phenolphthalein solution. As well as in a case with litmus, with the checked substance it is enough to add only several drops of the indicator to a test tube. In case solution is painted in bright crimson (red-violet) color, you will be able safely to state availability of alkali in a test tube. However in the silnoshchelochny environment phenolphthalein remains colourless therefore for distinction of silnoshchelochny and neutral environments it is more reasonable to use litmus.

Author: «MirrorInfo» Dream Team