pH scale MCQs Quiz Multiple Choice Questions & Answers

1. A colourless liquid sample was tested with pH paper strip. The colour of the strip changed reddish pink. The sample could be

1. tap water
2. sodium hydroxide solution
3. distilled water
4. ethanoic acid solution

2. A drop of a liquid sample was put on the pH paper. The colour of the pH paper turned blue. The liquid sample could be of

1. lemon juice
2. hydochloric acid
3. sodium bicarbonate solution
4. ethanoic acid

3. A drop of colourless liquid was placed on blue litmus paper. The litmus paper turned red. The liquid could be

1. dilute hydrochloric acid
2. dilute sodium hydroxide solution
3. distilled water
4. sodium bicarbonate solution

4. A drop of solution X is placed on a strip of a ph paper. A deep red color is produced. The solution X is

1. NaOH
2. HCL
3. Water
4. Sodium Bicarbonate

5. A few drops of a liquid X were added to distilled water. It was observed that the pH of the water decreased. The liquid X is

1. lemon juice
2. sugar solution
3. common salt solution
4. baking soda solution

6. A fruit juice is tested for its ph value. What could be its possible ph if it turns red

1. less than 3
2. more than 8
3. 7
4. between 6.5 and 7.5

7. A liquid sample turned red litmus paper blue. This indicates that the liquid sample is of

1. an alcohol
2. distilled water
3. sodium hydroxide solution
4. hydochloric acid

8. A little dilute hydrochloric acid is dropped on a pH paper. The colour of the pH paper turns to

1. dark pink
2. light green
3. light blue
4. bright yellow

9. A solution with pH = 0 is

1. acidic
2. basic
3. amphoteric
4. neutral

10. A student observed that the colour of pH paper changes to green when she dipped it in water. She added a few drops of concentrated hydrochloric acid to the water. The colour of pH paper would turn to

1. light red
2. apple green
3. dark blue
4. lemon yellow

11. A student tested the ph of distilled water and found that the colour of the ph paper changed it to green. He checked the ph again after dissolving common salt in it. the color of the ph paper this time is

1. green
2. yellow
3. red
4. blue

12. A student tested the pH of distilled water using paper and observed green colour. After adding a few drops of dilute NaOH solution, the pH was tested again. The colour change now observed would be

1. blue
2. green
3. red
4. orange

13. As the ph increases

1. acidic strength increases
2. basic strength increases
3. basic strength decreases
4. none of these

14. Bottle A contains oxalic acid and bottle B contains sodium carbonate solution. When pH paper is dipped in each of the solutions, the colour seen in A and B respectively will be

1. orange, blue
2. blue, orange
3. green, blue
4. orange, green

15. If the ph of a solution is 7.5, its nature is

1. neutral
2. strongly acidic
3. weakly acidic
4. basic

16. In an acid solution, the pH is

1. greater than p(OH)
2. less than p(OH)
3. equal to p(OH)
4. none of these

17. On putting two drops of dilute hydrochloric acid on the pH paper, the colour developed on the pH paper is

1. red
2. green
3. blue
4. violet

18. ph of a neutral solution

1. is more than 7
2. is less than 7
3. is 7
4. none of these

19. pH paper is prepared by dipping the strip into

1. Universal indicator
2. Blue litmus
3. Red litmus
4. Phenolphthalein

20. ph value of lime water is

1. 7
2. more than 7
3. less than 7
4. zero

21. Solid sodium bicarbonate was placed on a strip of pH paper. The colour of the strip

1. turned blue
2. did not change
3. turned green and suddenly yellow
4. turned light pink

22. Th two colours seen at the extreme end of the ph chart are

1. red, blue
2. red, green
3. green, blue
4. orange, green

23. The colour of the pH paper strip turned red when it was dipped into a solution. the solution colud be

1. dilute sodium bicarbonate solution
2. tap water
3. dilute sodium hydroxide solution
4. dilute hydrochloric acid

24. The correct method of finding the pH of a solution is to

1. heat the solution in a test tube and expose the ph paper to the vapours formed
2. pour few drops of the solution from the test tube on the ph paper
3. drop the ph paper in the solution
4. put a drop of the solution on the ph paper using a dropper

25. The pH is defined as

1. logarithm of hydrogen ion concentration
2. negative logarithm of hydrogen ion concentration.
3. logarithm of hydrogen ion concentration
4. only hydrogen ion concentration

26. The pH of a NaOH solution is 10. If water is added to it, its pH will

1. Remains same
2. Increases
3. Decreases
4. Becomes 7

27. the ph range of a universal indicator solution is

1. 3 to 14
2. 0 to 14
3. 11 to 14
4. 0 to 11

28. Which one of the following is not required to find the pH of a solution?

1. pH paper
2. litmus paper
3. Universal indicator
4. Standard ph value chart

29. Which one of the following solutions woulditmus you use to test the pH of a given sample?

1. Blue litmus solution
2. Red litmus solution
3. Universal indicator solution
4. Mixture of red and blue litmus solution