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What is the chemical formula of thymolphthalein?
C28H30O4
How do you pronounce thymolphthalein?
Thy-mol-phtha-lin
What are some indicators of acids?
Methyl Red, methyl orange, bromophenol blue, phenolphthalein, thymolphthalein, bromocresol green, bromothymol blue are all used as acid base indicators.
What is vanishing color?
Disappearing ink is a water-based acid-base indicator (pH indicator) that changes from a colored to a colorless solution upon exposure to air. The most common pH indicators for the ink are thymolphthalein (blue) or phenolphthalein (red or pink). The indicators are mixed into a basic solution that becomes more acidic upon exposure to air, causing the color change. Note that in addition to disappearing ink, you could use different indicators to make color-change inks, too.
How do you use phenophthalein to test for acids and bases?
Any titration is done to find the "equivalence point" - where the amount of titrant (strong base in your question) is equal to the amount of unknown (weak acid in your question). When the two are equal, the base has converted all the weak acid into it's conjugate base. An indicator should change color over the pH range that includes the equivalence point. In your question, when using a weak acid, what's left at the equivalence point is a strong conjugate base. The solution will have a slightly basic pH. Phenolphthalein has a colorless to pink transition over the range of pH 8-9.6, which is slightly basic. So it changes color across the equivalence point. So it makes a good indicator for the scenario you asked about. Thymol blue (color change slightly lower pH, weaker base, stronger acid) or Thymolphthalein (color change slightly higher pH, stronger base, weaker acid) may also be good choices.
What can we use as an indicator for acids and bases?
An indicator changes colour in the presense of acidic and basic solutions. It will be one colour for acidic solutions, and another color for basic solutions. With some indicators, the intensity of the color increases with the intensity of the acidity of 'basic-ness' of the solution. Cabbage is a natural indicator. An Acid turns pink and a base turns greenExamples of acid-base indicators: 1.) Litmus Paper acidic solutions will turn the blue litmus paper to red while basic solutions will turn the red litmus paper to blue2.) Congo Red basic solutions will change the color of the entire solution into blueThere are many indicators, some of them are :-Solution of red cabbage, or rose flower, strawberry, or cherry.These turn lighter(yellowish) in the presence of an acid, and more darker(violet) in the presence of a base.-Phenolphtaline : It is a chemical solution that remains colour-less in the presence of an acid, and violet in the presence of a base.-Red/Blue Litmus Paper : the RLP turns blue in the presence of a base, and the BLP turns red in the presence of an acid.And finally you can use a pH meter or pH paper to indicate the indentity of the solution.
