What is the pH value of the saliva before and after a meal ?

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

5, 7.4

7, 10

7.4, 5.8

2, 5

answer is C.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Concept- A healthy mouth has neutral pH. But intake of food causes a decrease in pH.
Our teeth are mainly made up of calcium. At a pH below 5.5, bacterial growth in the mouth increases and the tooth starts decaying.
Now, the pH of saliva is 7.4 at

25^{0} C

, which is alkaline in nature. After a meal, this pH decreases to 5.8. Now,the tooth decay begins when the pH in the mouth is lower than 5.5. As acidic environments corrode tooth enamel and eventually weaken it, thus to prevent the decay of tooth enamel, toothpaste should be basic in nature.
Therefore, toothpaste, which is generally alkaline, can neutralise excess acid and prevent tooth decay.
Hence, the correct option is (3).

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE