Solution:Concept- The litmus paper is a type of paper that changes colour according to the acidity of the solution it is dipped in and hence can be used to measure acidity.
The pH is a measure of the acidic nature or basic nature of a substance. It is also used to determine the hydrogen ion concentration in a solution.
For acidic substances, .
For neutral substances,
For basic substances,
There are some natural foods that are acidic in nature. Tomato is one of them and it is acidic due to the presence of lycopene.
Therefore, the range of tomato juice is between to .
Hence, the correct option is 2.