question_answer 54)

  A student prepared solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since, both the solutions are colourless, how will she distinguish between the two?        

Answer:

  In the absence of litmus, any other indicator like methyl orange, phenolphthalein, etc., can be used. Otherwise a natural indicator like turmeric can also be used. Some common indicators with characteristic colours are tabulated below                

S. No.	Indicator	Colour in acidic solution	Colour in neutral solution	Colour in basic solution
1. 2. 3. 4.	Litmus Phenolphthalein Methyl orange Turmeric juice	Red Colourless Red/pink Yellow	Purple Colourless Orange Yellow	Blue Pink Yellow Reddish Brown