Grade 7 Integrated Science – Acids,bases and indicators Quiz

1. What is an indicator?

Is a substance that changes colour when added to a basic or an acidic solution.
Is anything that can be used to give directions.
Is used to manufacture antibiotics.
Is anything that changes colour.
Explanation:

2. There are.......types of indicators.

4
1
3
2
Explanation:

3. Which of the following are types of indicators?

Hospital and plants extract indicators
Plant extract and Laboratory indicators
Animal extract and Laboratory indicators
Bougainvillea grow and plant extract indicators
Explanation:

4. Which one is not a laboratory indicator?

Litmus solution
Methyl orange
Propane
Phenolphthalein
Explanation:

5. Litmus solution turns.......in acids.

Blue
Red
Yellow
Green
Explanation:

6. Litmus solution turns.......in bases .

Yellow
Blue
Red
Green
Explanation:

7. Which of the is a basic solution?

Baking powder
Distilled water
Lemon juice
Phenolphthalein
Explanation:

8. What is the colour observed when phenolphthalein indicator is added to a neutral solution?

Red
Blue
Pink
Colourless
Explanation:

9. What is the colour observed when phenolphthalein indicator is added to a basic solution?

Pink
Odourless
Coloured
Colourless
Explanation:

10. What is the colour observed when phenolphthalein indicator is added to an acidic solution?

Colourless
Pink
Red
Blue
Explanation:

11. What is the colour observed when litmus solution is added to a neutral solution?

Remains purple
Blue
Red
Green
Explanation:

12. What is the colour observed when litmus solution is added to an acidic solution?

Blue
Yellow
Red
Purple
Explanation:

13. What is the colour observed when litmus solution is added to a basic solution?

Black
Blue
Purple
Red
Explanation:

14. What is the colour observed when Methyl orange indicator is added to a neutral solution?

Remains orange
Yellow
Blue
Pink
Explanation:

15. What is the colour observed when Methyl orange indicator is added to a basic solution?

Green
Red
Blue
Yellow
Explanation:

16. What is the colour observed when Methyl orange indicator is added to an acidic solution?

Orange
Yellow
Purple
Pink
Explanation:

17. How can we differentiate between strong and weak acids or bases?By using..........

Universal indicators
Phenolphthalein
Litmus paper
Methyl orange
Explanation:

18. Neutral substances have a pH value of?

1
14
8
7
Explanation:

19. Acids have a pH value of?

Between 8 to 14
Between 6 to 7
7
less than 7
Explanation:

20. Strong acids have a pH value ranging from?

7 to 14
8 to 14
0 to 3
4 to 6
Explanation:

21. Weak acids have a pH value ranging from?

7 to 14
8 to 14
1 to 2
4 to 6
Explanation:

22. Bases have a pH value ranging from?

8 to 14
4 to 6
1 to 2
7 to 14
Explanation:

23. Weak bases have a pH value ranging between?

8 to 10
6 to 7
1 to 2
11 to 14
Explanation:

24. Strong bases have a pH value ranging from?

6 to 7
8 to 10
8 to 14
11 to 14
Explanation:

25. Which one are strong acids?

Lemon juice and orange juice
Orange juice and Hydrochloric acid
Lemon juice and Sulphuric acid
Sulphuric acid and Hydrochloric acid
Explanation:

26. Which of the following are weak acids?

Lemon juice and sodium hydroxide
Lemon juice and Orange juice
Distilled water and Calcium hydroxide
Calcium hydroxide and Orange juice
Explanation:

27. Which of the following are Neutral solutions?

Baking powder and sodium hydroxide
Sulphuric acid and Hydrochloric acid
Distilled water and Sodium chloride
Water and sodium hydroxide
Explanation:

28. Identify weak bases.

Calcium hydroxide and baking powder solution
Sodium chloride and sodium hydroxide
Sodium chloride and water
Liquid soap and orange juice
Explanation:

29. Identify strong bases.

Liquid soap and sodium hydroxide
Orange juice and sodium hydroxide
Sulphuric acid and lemon juice
Calcium hydroxide and hydrochloric acid
Explanation:

30. Identify two uses of acid- base indicators.

Testing of soil and manufacture of products
Manufacture for products and Detergents
Fertilizers and testing of soil
Testing for pollution and Liming of soils
Explanation:

31. Which one is an application of acids in day-to-day life?

Liming of soils
Detergents
Making fertilizers
Some acids are used to clean metallic surface
Explanation:

32. The following are uses of bases in day-to-day life.Which one is not?

Fertilizer and Detergents
Cleaning metallic surface
Antacid tablets
Liming of soils
Explanation:

33. Which of the following is a property of acids?

Feels slippery
Tastes sweet
Turns blue litmus paper red
Conducts electricity
Explanation:

Acids turn blue litmus paper red. Blue litmus paper remains blue when in contact with bases.

34. Which of the following is a common indicator for acids?

Methylene blue
Phenolphthalein
Red cabbage juice
Bromothymol blue
Explanation:

Red cabbage juice changes color to indicate the presence of acids. It turns red in acids and green in bases.

35. Which of the following is a characteristic of bases?

Feels sticky
Has a pH less than 7
Turns red litmus paper blue
Tastes sour
Explanation:

Bases turn red litmus paper blue. Red litmus paper remains red when in contact with acids.

36. Which of the following substances is an example of a strong acid?

Sodium hydroxide
Vinegar
Hydrochloric acid
Lemon juice
Explanation:

Hydrochloric acid is a strong acid that can fully dissociate in water to release a large number of hydrogen ions.

37. How does an indicator help in distinguishing between acids and bases?

It tastes sour in bases
It feels slippery in acids
It changes color in the presence of acids
It conducts electricity in bases
Explanation:

Indicators change color depending on the pH of the solution, helping to differentiate between acidic and basic substances.

38. Which of the following is a household product that is acidic?

Baking soda
Ammonia
Bleach
Lemon juice
Explanation:

Lemon juice contains citric acid, which gives it its characteristic sour taste and acidic properties.

39. What happens to the pH value when an acid is added to water?

pH remains constant
pH fluctuates
pH decreases
pH increases
Explanation:

When an acid is added to water, the concentration of hydrogen ions increases, causing the pH to decrease and become more acidic.

40. Which substance is commonly used to neutralize acids in a laboratory setting?

Hydrochloric acid
Acetic acid
Carbon dioxide
Sodium hydroxide
Explanation:

Sodium hydroxide is a strong base that can neutralize acids by reacting with hydrogen ions to form water and a salt.

41. What color does phenolphthalein turn in the presence of a base?

Red
Purple
Yellow
Green
Explanation:

Phenolphthalein turns purple in the presence of bases, indicating the basic nature of the solution.

42. Which of the following is a characteristic of a neutral solution?

Feels slippery
pH of 7
Tastes sour
Turns blue litmus paper red
Explanation:

A neutral solution has a pH of 7, indicating an equal concentration of hydrogen and hydroxide ions.