Advertisements
Advertisements
प्रश्न
Explain why phenolphthalein is used as an indicator of acid-base titration.
संक्षेप में उत्तर
उत्तर
phenolphthalein is a complex weak organic acid (HPh). Its undissociated molecule (HPh) is colourless while it's an ion (Ph-) is pink in colour. pH range of phenolphthalein is 8 - 9.8.
In acid-base titration as the medium changes from acidic to basic, the following equilibrium shifts to right.
HPh ⇌ H+ + Ph- and the solution turns pink from colourless giving its endpoint. when medium changes to acidic, equilibrium shifts to left and the solution becomes colourless.
shaalaa.com
Use in Redox Titration
क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
