railway DFCCIL Junior Executive 2023 (CBT 1 & CBT 2) Mock Test General Science Chemistry Equilibrium
Which of the following statements is correct?
1
Living organisms can survive a wide range of pH change.
2
When pH of rain water is less than 8.2, it is called acid rain.
3
Our body works within the pH range of 7.0 to 7.8.
4
Tooth decay starts when the pH of the mouth is lower than 1.5.