This method utilizes the pH-sensitive property of phenolphthalein indicator. It changes color from colorless to pink/purple in an alkaline medium.
Fill in the blank appropriately. A trap laid for apprehending a Govt. employee taking bribe used phenophthalein powder coated currency notes. A solution of sodium carbonate sprinkled on the notes must turn _______ for lending proof for the crime.
Asked in MPSC CS Prelims 2013 · Topic: Acid, Base and Salt (Acid-Base Indicators (Litmus, Phenolphthalein, Methyl Orange, Universal Indicator))
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