Résumé
Mixing a test portion to which a mixed indicator (bromocresol green/alizarin red S) has been added with water by shaking. Comparison of the colour of the aqueous layer with that of a neutral solution of the indicator.
Mixing a test portion to which a mixed indicator (bromocresol green/alizarin red S) has been added with water by shaking. Comparison of the colour of the aqueous layer with that of a neutral solution of the indicator.