Chemistry 9th Chap 10 : Topic 5 - Maryam Publications

Chemistry Chapter 10 : Topic 5

Bases and Alkalis

1 / 20

Which statement correctly defines a base?

A) An oxide or hydroxide of a metal that can neutralize acids.

B) A substance that always dissolves in water to form acids.

C) A compound that must be soluble in water to act as a base.

D) A substance that reacts with metals to produce hydrogen gas only.

2 / 20

Which of the following best distinguishes an alkali from a base?

A) Alkalis are only found in liquid state.

B) Alkalis do not react with acids, while bases do.

C) Alkalis are always metal oxides while bases are hydroxides.

D) Alkalis are water-soluble bases, while bases may or may not be soluble in water.

3 / 20

Which of the following is NOT an alkali?

A) CuO

B) KOH

C) Ca(OH)₂

D) NaOH

4 / 20

Why is sodium hydroxide classified as an alkali?

A) It dissolves in water and produces OH⁻ ions.

B) It is a gas at room temperature.

C) It is a metal oxide.

D) It reacts only with non-metals.

5 / 20

Which statement is correct about all alkalis?

A) All alkalis are insoluble in water.

B) All alkalis are bases, but not all bases are alkalis.

C) All alkalis are metal oxides.

D) All alkalis are acids in disguise.

6 / 20

Which of the following is a base but NOT an alkali?

A) KOH

B) CuO

C) NaOH

D) NH₄OH

7 / 20

What happens when calcium oxide reacts with water?

A) It forms Ca(OH)₂ which acts as an alkali.

B) It forms an acid.

C) It remains unchanged.

D) It forms salt and water.

8 / 20

Which of the following best describes ammonia in water?

A) Strong acid

B) Weak alkali

C) Insoluble base

D) Metal oxide

9 / 20

Why is magnesium hydroxide considered a weak alkali?

A) It is highly soluble in water.

B) It is slightly soluble in water.

C) It is completely insoluble in water.

D) It is a metal oxide.

10 / 20

Which pair correctly represents both bases?

A) CuO and MgO

B) HCl and H₂SO₄

C) CO₂ and SO₂

D) NaCl and KCl

11 / 20

Which of the following is TRUE about metal oxides?

A) Metal oxides are always soluble in water.

B) Many metal oxides act as bases.

C) Metal oxides do not react with acids.

D) All metal oxides are acids.

12 / 20

Which of the following is a correct characteristic of alkalis?

A) They are soluble bases producing OH⁻ ions in water.

B) They are all insoluble metal oxides.

C) They never react with acids.

D) They are always gases.

13 / 20

Which substance will increase OH⁻ concentration in water?

A) CO₂

B) SO₂

C) HCl

D) NaOH

14 / 20

Which base is least likely to be classified as an alkali?

A) NaOH

B) Fe₂O₃

C) KOH

D) Ca(OH)₂

15 / 20

What is the key requirement for a base to be called an alkali?

A) It must be a gas.

B) It must be soluble in water.

C) It must be acidic in nature.

D) It must contain carbon.

16 / 20

Which of the following correctly shows a base that is NOT an alkali?

A) KOH

B) NaOH

C) CuO

D) Ca(OH)₂

17 / 20

Why is potassium hydroxide classified as an alkali?

A) It is a metal oxide.

B) It reacts only with metals.

C) It is insoluble in water.

D) It produces OH⁻ ions in aqueous solution.

18 / 20

Which statement about bases and alkalis is correct?

A) Alkalis do not neutralize acids.

B) All bases are alkalis.

C) Alkalis are a special type of base.

D) No base is soluble in water.

19 / 20

Which of the following best represents an insoluble base?

A) NH₄OH

B) NaOH

C) CuO

D) KOH

20 / 20

What is the correct relationship between bases and alkalis?

A) All bases are soluble.

B) Alkalis are broader than bases.

C) Alkalis are a type of base that is soluble in water.

D) Bases are a type of alkali.

Your score is

0%