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A roll of universal indicator paper Colors of universal indicator. A universal indicator is a pH indicator made of a solution of several compounds that exhibit various smooth colour changes over a wide range pH values to indicate the acidity or alkalinity of solutions. A universal indicator can be in paper form or present in a form of a ...
Hence, a pH indicator is a chemical detector for hydronium ions (H 3 O +) or hydrogen ions (H +) in the Arrhenius model. Normally, the indicator causes the color of the solution to change depending on the pH. Indicators can also show change in other physical properties; for example, olfactory indicators show change in their odor.
Phenolphthalein (/ f ɛ ˈ n ɒ l (f) θ ə l iː n / [citation needed] feh-NOL(F)-thə-leen) is a chemical compound with the formula C 20 H 14 O 4 and is often written as "HIn", "HPh", "phph" or simply "Ph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations.
Three different points in an acid-base titration using phenolphthalein as the indicator. Phenolphthalein is widely recognized as one of the most commonly used acid-base indicators in chemistry. [12] Its popularity is because of its effectiveness in a broad pH range and its distinct colour transitions. [12]
Bromophenol is also used as a colour marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis.Since bromophenol blue carries a slight negative charge at moderate pH, it will migrate in the same direction as DNA or protein in a gel; the rate at which it migrates varies according to gel density and buffer composition, but in a typical 1% agarose gel in ...
A hydrogencarbonate indicator (hydrogencarbonate indicator) is a type of pH indicator that is sensitive enough to show a color change as the concentration of carbon dioxide gas in an aqueous solution increases. The indicator is used in photosynthesis and respiration experiments to find out whether carbon dioxide is being liberated. [1]
It is used as a pH indicator in applications such as growth mediums for microorganisms and titrations. In clinical practise, it is commonly used as a diagnostic technique. The most common use of bromocresol green is to measure serum albumin concentration within mammalian blood samples in possible cases of kidney failure and liver disease.
When used as an indicator in an EDTA titration, the characteristic blue end-point is reached when sufficient EDTA is added and the metal ions bound to the indicator are chelated by EDTA, leaving the free indicator molecule. Eriochrome Black T has also been used to detect the presence of rare earth metals. [2]