Answer:
Lemon juice has lowest pH.
Step-by-step explanation:
pH is the negative log of hydrogen ion concentration. By increasing the Hydrogen ion concentration pH will decrease.
pH = -log [H⁺]
According to pH scale,
The pH of 7 is consider neutral. The pH below the 7 is consider acidic and above the 7 is basic.
The sodium hydroxide is strongest base because it fully dissociate into ions.
It dissociate to gives the sodium and hydroxyl ions and solution became more basic.
NaOH → Na⁺(aq) + OH⁻(aq)
Its pH is 12. It is also known as caustic soda.
The pH of blood is vary from 7.35 - 7.45. it is slightly alkaline.
The pH of lemon juice is ranging between 2-3.
The pH of tap water is ranging between 6-8.5.
From above given information it can be noticed that lemon juice have lowest pH i.e 2-3. It is acidic, because its pH is less than 7.