Answer:
The correct litmus test for an acid is:
blue litmus turns red
Step-by-step explanation:
Litmus paper : It is a paper which contains 14 -15 dyes obtained from Lichens
It is also called Acid-Base Indicator
It is used to test whether the given solution is acidic or not.
If the solution is acidic the litmus turns Red
If the solution is basic the litmus turns Blue
How to perform Litmus Test :
Place the drop of given solution over the litmus paper.
If the Litmus paper is Blue initially and On adding a drop of given solution , it turn red then it indicate that the solution is acid with pH = 3 to 7
Red litmus paper does not change its color if the solution is acidic .
If the Litmus paper is Red initially and On adding a drop of given solution , it turn Blue then it indicate that the solution is alkaline . pH= 4 to 12
Blue litmus does not change its color in the presence of alkaline solution.