Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color...
Question:
Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.20 m KOH.
pH Indicator:
A pH indicator is a weak acid used to visually monitor the pH of a solution, usually to determine the endpoint of an acid-base reaction. The indicator exhibits different colors depending on if the solution pH is below or above the pKa of the indicator. This color change is not instantaneous at a precise pH. In general an indicator will have a color range over the pH range of its pKa +/- 1.
Answer and Explanation: 1
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0.20 M KOH is a strong base and will fully dissociate in solution to produce 0.20 M of hydroxide ion. This will create a strongly basic solution:
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Acid-Base Indicator: Definition & Concept
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Chapter 11 / Lesson 11
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Learn about acid-base indicators. Understand what acid-base indicators are, how they work to determine if a solution is acidic or basic, and see the examples.
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