Std 10 Samajik Vignan paper solution

When the strip of pH paper was put in a given solution the pH paper changes to orange red. The given solution is most likely to be of:

Blue litmus paper turns on contact with an acidic solution.

A blue litmus paper was first dipped in dil. HCl and then in dil. NaOH solution. It was observed that the color of litmus paper

When a red litmus paper treated with sodium hydroxide solution , the colour of the litmus paper becomes

A blue litmus paper was first dipped in dil .HCl and then in dil .NaOH solution .It was observed that the colour of the litmus paper