Grade 7 Integrated Science – Acids,bases and indicators Quiz

1. What is an indicator?

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

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

4
2
3
1
Explanation:

3. Which of the following are types of indicators?

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

4. Which one is not a laboratory indicator?

Litmus solution
Propane
Methyl orange
Phenolphthalein
Explanation:

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

Yellow
Blue
Red
Green
Explanation:

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

Red
Blue
Green
Yellow
Explanation:

7. Which of the is a basic solution?

Distilled water
Phenolphthalein
Baking powder
Lemon juice
Explanation:

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

Colourless
Blue
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?

Blue
Pink
Colourless
Red
Explanation:

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

Remains purple
Blue
Green
Red
Explanation:

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

Red
Blue
Yellow
Purple
Explanation:

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

Red
Blue
Black
Purple
Explanation:

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

Pink
Blue
Yellow
Remains orange
Explanation:

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

Red
Green
Blue
Yellow
Explanation:

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

Yellow
Purple
Pink
Orange
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?

7
8
1
14
Explanation:

19. Acids have a pH value of?

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

20. Strong acids have a pH value ranging from?

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

21. Weak acids have a pH value ranging from?

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

22. Bases have a pH value ranging from?

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

23. Weak bases have a pH value ranging between?

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

24. Strong bases have a pH value ranging from?

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

25. Which one are strong acids?

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

26. Which of the following are weak acids?

Calcium hydroxide and Orange juice
Lemon juice and Orange juice
Distilled water and Calcium hydroxide
Lemon juice and sodium hydroxide
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.

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

29. Identify strong bases.

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

30. Identify two uses of acid- base indicators.

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

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

Liming of soils
Making fertilizers
Detergents
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?

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

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

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

Bromothymol blue
Red cabbage juice
Methylene blue
Phenolphthalein
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
Turns red litmus paper blue
Has a pH less than 7
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?

Hydrochloric acid
Lemon juice
Vinegar
Sodium hydroxide
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
Baking soda
Lemon juice
Ammonia
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 increases
pH fluctuates
pH remains constant
pH decreases
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?

Carbon dioxide
Acetic acid
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
Green
Red
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
pH of 7
Turns blue litmus paper red
Explanation:

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

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