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What does phenolphthalein indicate when the solution is basic?
- a)It turns dark pink
- b)It turns green
- c)It remains colourless
- d)It turns blue
Correct answer is option 'A'. Can you explain this answer?
Most Upvoted Answer
What does phenolphthalein indicate when the solution is basic?a)It tur...
Understanding Phenolphthalein
Phenolphthalein is a common pH indicator used in titrations and various chemical experiments to determine the acidity or basicity of a solution.
Behavior in Basic Solutions
- In basic solutions (pH above 8.2), phenolphthalein undergoes a structural change that causes it to turn dark pink.
- This color change occurs because phenolphthalein has a specific molecular structure that is sensitive to the pH of the solution.
Color Change Mechanism
- In acidic solutions (pH below 7), phenolphthalein remains colorless.
- As the pH increases, the solution becomes less acidic and more basic, leading to the deprotonation of the phenolphthalein molecule.
- This deprotonation changes its structure, allowing it to absorb light differently and reflect a pink color.
Significance of the Color Change
- The transition from colorless to dark pink indicates that the solution has crossed the neutral point and entered a basic range.
- This visual cue is crucial in laboratory settings, as it helps in determining the endpoint of titrations involving strong bases.
Conclusion
- Therefore, when a solution is basic, phenolphthalein turns dark pink, making option 'A' the correct answer. This property is widely utilized in chemistry to assess the pH of solutions effectively.
Phenolphthalein is a common pH indicator used in titrations and various chemical experiments to determine the acidity or basicity of a solution.
Behavior in Basic Solutions
- In basic solutions (pH above 8.2), phenolphthalein undergoes a structural change that causes it to turn dark pink.
- This color change occurs because phenolphthalein has a specific molecular structure that is sensitive to the pH of the solution.
Color Change Mechanism
- In acidic solutions (pH below 7), phenolphthalein remains colorless.
- As the pH increases, the solution becomes less acidic and more basic, leading to the deprotonation of the phenolphthalein molecule.
- This deprotonation changes its structure, allowing it to absorb light differently and reflect a pink color.
Significance of the Color Change
- The transition from colorless to dark pink indicates that the solution has crossed the neutral point and entered a basic range.
- This visual cue is crucial in laboratory settings, as it helps in determining the endpoint of titrations involving strong bases.
Conclusion
- Therefore, when a solution is basic, phenolphthalein turns dark pink, making option 'A' the correct answer. This property is widely utilized in chemistry to assess the pH of solutions effectively.
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Community Answer
What does phenolphthalein indicate when the solution is basic?a)It tur...
When phenolphthalein is added to a basic solution, it changes its color to dark pink. This change helps us know if a solution is basic or not. So, when you see the pink color, you can tell that the solution is basic.
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What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer?
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What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer? for Class 7 2025 is part of Class 7 preparation. The Question and answers have been prepared according to the Class 7 exam syllabus. Information about What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 7 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer?.
What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer? for Class 7 2025 is part of Class 7 preparation. The Question and answers have been prepared according to the Class 7 exam syllabus. Information about What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 7 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for What does phenolphthalein indicate when the solution is basic?a)It turns dark pinkb)It turns greenc)It remains colourlessd)It turns blueCorrect answer is option 'A'. Can you explain this answer?.
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