pH scale MCQ Questions and Answers for Practice

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