The pH value of any solution is a number which simply represents the acidity and basicity of that solution. The pH value of any solution is numerically equal to the logarithm of the inverse of the hydrogen ion (H+) concentration.
Hence, the pH of a solution is referred as the negative logarithm of hydrogen ion. In this article MCQs are given related to pH scale which will help in various exams preparation and also help to build the clarity of the concept.
1. Which of the following statement is correct regarding pH Scale?
(i) It is the negative logarithm of H+ ion concentration of a given solution.
(ii) It is the positive logarithm of H+ ion concentration of a given solution.
(iii) It is a 14 point scale.
(iv) pH is an example of an extrinsic property.
Correct Options are:
A. (i) and (iii)
B. (ii) and (iii)
C. (i), (iii) and (iv)
D. Only (ii)
2. What is the neutral value of pH scale?
A. Less than 5
B. Equal to 7
C. Less than 8
D. Less than 10
3. Who had invented the pH Scale?
A. S.P.L Sorenson
B. Benjamin Franklin
C. Henry Moseley
D. Wilhelm Rontgen
4. In which of the following field pH scale is important for measurements?
C. Food Science
D. All of the above
5. What is the pH value of very strong acid solution?
A. Less than 7
B. Less than 5
C. Less than 2
D. Less than zero
6. Why we measure the pH of sea water?
A. It helps in corrosion research.
B. It helps in agricultural activity.
C. It helps in fermentation.
D. It helps in sterilization.
7. Which statement is correct regarding Buffer Solution?
A. It is a solution whose pH change when small amount of an acid or base is added in it.
B. It is a solution whose pH does not change when small amount of an acid or base is added in it.
C. It does not use pH value as constant in wide variety of chemical applications.
D. The solution of methanoic acid is an example of effective buffer solution.
8. What is the pH value of saliva after meal?
D. Less than 4
9. What is the pH value of pure water?
A. Less than 7
B. Greater than 7
C. Equal to 7
D. Greater than 14
10. How we will come to know that a given solution is acidic?
A. If its pH value is less than 7
B. If its pH value is greater than 7
C. If its pH value is less than 5
D. If its pH value is 5
11. What will be the litmus test if the solution is basic?
A. Red litmus will turn to blue
B. Blue litmus will turn to red
C. No change in colour
D. It will change into orange pink.
12. What is the ph value of toothpaste?
A. It ranges from 3 to 10 depending upon the additives added in it.
B. It ranges from 5 to 12 depending upon the additives added in it.
C. It ranges from 7 to 14 depending upon the additives added in it.
D. It ranges from 6 to 8 depending upon the additives added in it.
13. What is the pH value of pure alcohol?
14. Kw is the ionisation constant for water and its value is:
A. 1 x 10-7
B. 1 x 107
C. 1 x 1014
D. 1 x 10-14
15. An acidic solution has:
A. Less concentration of hydrogen ions than hydroxide ions.
B. More concentration of hydroxide ions than hydrogen ions.
C. More concentration of hydroxyl ions.
D. Equal concentration of hydroxide and hydrogen ions.