Question

Iers there any trick to remember acids changes blue litmus paper to red and red litmus paper to blue??

Answer 1

Acid changes blue litmus to red-
As we know acids are dangerous and red colour signifies colour of danger. So remember that resultant colour of litmus will be red whether it is blue or red litmus.
Base changes red litmus to blue-
The initial of base is B and initial of blue is also B. So it is easy to remember that resultant colour of litmus will be blue whether is red or blue litmus.