Grade 7 Integrated Science – Acids,bases and indicators Quiz

1. What is an indicator?

Is anything that changes colour.
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.
Explanation:

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

3
2
1
4
Explanation:

3. Which of the following are types of indicators?

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

4. Which one is not a laboratory indicator?

Methyl orange
Litmus solution
Propane
Phenolphthalein
Explanation:

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

Green
Yellow
Blue
Red
Explanation:

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

Red
Yellow
Green
Blue
Explanation:

7. Which of the is a basic solution?

Distilled water
Baking powder
Phenolphthalein
Lemon juice
Explanation:

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

Blue
Colourless
Pink
Red
Explanation:

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

Coloured
Colourless
Pink
Odourless
Explanation:

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

Pink
Red
Colourless
Blue
Explanation:

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

Green
Blue
Remains purple
Red
Explanation:

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

Blue
Red
Purple
Yellow
Explanation:

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

Blue
Black
Purple
Red
Explanation:

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

Yellow
Remains orange
Pink
Blue
Explanation:

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

Red
Yellow
Blue
Green
Explanation:

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

Orange
Pink
Purple
Yellow
Explanation:

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

Litmus paper
Methyl orange
Phenolphthalein
Universal indicators
Explanation:

18. Neutral substances have a pH value of?

8
1
7
14
Explanation:

19. Acids have a pH value of?

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

20. Strong acids have a pH value ranging from?

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

21. Weak acids have a pH value ranging from?

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

22. Bases have a pH value ranging from?

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

23. Weak bases have a pH value ranging between?

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

24. Strong bases have a pH value ranging from?

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

25. Which one are strong acids?

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

26. Which of the following are weak acids?

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

27. Which of the following are Neutral solutions?

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

28. Identify weak bases.

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

29. Identify strong bases.

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

30. Identify two uses of acid- base indicators.

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

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

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

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

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

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

Turns blue litmus paper red
Conducts electricity
Tastes sweet
Feels slippery
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?

Phenolphthalein
Red cabbage juice
Bromothymol blue
Methylene 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?

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

Hydrochloric acid
Vinegar
Sodium hydroxide
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 changes color in the presence of acids
It feels slippery in 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?

Bleach
Lemon juice
Ammonia
Baking soda
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 increases
pH decreases
pH fluctuates
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?

Acetic acid
Carbon dioxide
Hydrochloric acid
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?

Purple
Yellow
Red
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?

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

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