The pH scale ranges from 0 to 14.
A pH of 7 is neutral.
A pH less than 7 is acidic.
A pH greater than 7 is basic.
So according to the definition, we can identify the given samples.
1. Lemon juice pH 2.2 -- acidic
2. Salt solution pH 7 ---- neutral
3. Baking soda pH 9 ---- basic
4. Bleach pH 13 --- basic
5. Tomato juice pH 4 --- acidic
6. Gastric juices pH 1 --- acidic
