Question

Which colour appears when few drops of phenolphthalein are put into a test tube containing lime water?
1. Yellow
2. Pink
3. Orange
4. Colourless
5. None of the above/More than one of the above.

Answer 1

Correct Answer - Option 2 : Pink

The correct answer is Pink.

• The chemical compound phenolphthalein has the formula C₂₀H₁₄O₄ and is commonly abbreviated as "HIn" or "phph" in shorthand notation.
• Phenolphthalein is frequently used as an indicator.
• It's a phthalein dye, which means it's a type of dye.
• Phenolphthalein in Acidic solutions turns colourless
• Phenolphthalein in basic solutions turns pink in colour. 

Explanation:

• Lime water is basic in nature. 
• Calcium hydroxide is the chemical term for lime water, which has the formula Ca(OH)₂.
• When Phenolphthalein, it turns pink as lime water is basic in nature.
• Hence, the correct answer is - Pink.