chapter_7 (acid & bases)

8/8/2019 Chapter_7 (Acid & Bases)

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CURICULUM DEVELOPMENT CENTRE

PRETEST

TOPIC: ACID AND BASE Time: 15 minutes

Answerallquestions. Write your answers in the spaces provided in the table below.

Pretest Answer Table

Question No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Answer

1 What is the meaning of an acid?

A Acid is a substance that undergoes high rate of ionisation

B Acid is a substance that changes red litmus to blue

C Acid is a substance ionises in water to produce hydrogen ion, H+

D Acid is a substance ionises in water to produce hydroxide ion, OH-

2 Which of the following is true of a weak alkali?

A The pH value is less than 7

B Able to change blue litmus paper to red

C Ionises partially in water to produce hydroxide ions, OH-

D Ionises partially in water to produce hydrogen ions, H+

3 Which of the following is true of a weak acid?

A Ionises partially in water to produce hydroxide ions, OH-

B The pH value is more than 7

C Able to change red litmus paper to blue

D Ionises partially in water to produce hydrogen ions, H+

4 When hydrogen chloride is passed through toluene, the solution produced will

A change blue litmus to red

B consist of hydrogen chloride molecules

C react with zinc to produce hydrogen gas

D release carbon dioxide when added with calcium carbonate

5 Which of the following 0.5 mol dm-3 solutions is the weak acid?

A Nitric acid

B Ethanoic acid

C Sulphuric acid

D Hydrochloric acid

6 The pH value of a hydrochloric acid is 1 and an oxalic acid is 4. It means

A oxalic acid is a weak acid

B hydrochloric acid is a weak acid

C degree of dissociation of both acids are the same


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D the molarity of hydrogen ions in both acids are the same

7 Which of the following solutions will turn blue litmus paper red?

A Ethanol in water

B Ammonia in water

C Sulphur dioxide in waterD Hydrogen chloride in toluene

8 A solution has a pH value of 11. Which of the following is true about the solution?

A It turns blue litmus paper to red

B It reacts violently with magnesium

C Its concentration of OH- ion is greater than H+ ions

D It reacts with sodium hydroxide to produce salt and water

9 Which of the following solutions show the pH value of more than 7?

I 0.1 moldm-3 ammonium solution

II 0.1 moldm-3 sodium hydroxide solutionIII 0.1 moldm-3 ethanoic acid

IV 0.1 moldm-3 hydrochloric acid

A I and II only

B I and III only

C II and IV only

D III and IV only

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0

0.05 moles of hydrochloric acid, HCl, is dissolved in distilled water to form 0.1dm3

solution. What is the concentration of the solution in moldm-3?

A 0.02

B 0.05

C 0.50

D 5.00

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8 g of sodium hydroxide is dissolved in distilled water to form 250 cm3 solution. What

is the molarity of the sodium hydroxide solution?

[Relative atomic mass: H,1 ; Na,23; O,16]

A 0.05 mol dm-3

B 0.20 mol dm-3

C 0.60 mol dm-3

D0.80 mol dm

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2

What is the mass of calcium hydroxide in 200cm3 of 0.5 moldm-3 calcium hydroxide

solution?

[Relative atomic mass; H, 1 ;O, 16; Ca, 40]

A 3.7 g

B 7.4 g

C 15.8 g

D 74.0 g

91


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Pretest Answer Table

Question No. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

Answer C C D B B A C C A C D B

92

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