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2. Phenolphthalein - Wikipedia

   en.wikipedia.org/wiki/Phenolphthalein

   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.

3. pH indicator - Wikipedia

   en.wikipedia.org/wiki/PH_indicator

   In and of themselves, pH indicators are usually weak acids or weak bases. The general reaction scheme of acidic pH indicators in aqueous solutions can be formulated as: HInd (aq) + H 2 O (l) ⇌ H 3 O + (aq) + Ind − (aq) where, "HInd" is the acidic form and "Ind −" is the conjugate base of the indicator. Vice versa for basic pH indicators ...

4. Phthalein dye - Wikipedia

   en.wikipedia.org/wiki/Phthalein_dye

   Chemical structure of phenolphthalein, a common phthalein dye. Phthalein dyes are a class of dyes mainly used as pH indicators, due to their ability to change colors depending on pH. [1] They are formed by the reaction of phthalic anhydride with various phenols. They are a subclass of triarylmethane dyes. Common phthalein dyes include ...

5. Acid–base titration - Wikipedia

   en.wikipedia.org/wiki/Acid–base_titration

   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] Its sharp and easily detectable colour changes makes phenolphthalein a valuable tool for determining the endpoint of acid-base ...

6. Universal indicator - Wikipedia

   en.wikipedia.org/wiki/Universal_indicator

   A roll of universal indicator pape 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 solution ...

7. Equivalence point - Wikipedia

   en.wikipedia.org/wiki/Equivalence_point

   An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are also frequently used. A drop of indicator solution is added to the titration at the start; when the color changes the endpoint has been reached, this is an approximation of the equivalence point. Conductance

8. Kastle–Meyer test - Wikipedia

   en.wikipedia.org/wiki/Kastle–Meyer_test

   The two electrons are supplied by phenolphthalein: HOOH + 2 e − + 2 H + → 2 H 2 O. The consumption of protons during the course of the reaction has the effect of raising the pH of the solution, but the amount of base produced is negligible compared to the amount of base already present in the reagent mixture.

9. Base (chemistry) - Wikipedia

   en.wikipedia.org/wiki/Base_(chemistry)

   Reactions with indicators: bases turn red litmus paper blue, phenolphthalein pink, keep bromothymol blue in its natural colour of blue, and turn methyl orange-yellow. The pH of a basic solution at standard conditions is greater than seven. Bases are bitter. [5]