Nature of Cl 2 ​ O 7 ​ (Acidic/Basic).

1. Nature of Cl₂O₇ (Acidic/Basic) +

Correct Answer

Cl₂O₇ is an acidic oxide.

Detailed Explanation

Cl₂O₇ is dichlorine heptoxide. It is the highest oxide of chlorine, in which chlorine has an oxidation state of +7.

2Cl + 7O = 0
2x + 7(−2) = 0
x = +7

It is a non-metal oxide. Oxides of non-metals generally show acidic character, especially when the element is in a high oxidation state. Cl₂O₇ reacts with water to form perchloric acid:

Cl₂O₇ + H₂O → 2HClO₄

Since it produces HClO₄, a strong acid, the oxide is classified as an acidic oxide.

Periodic Trend Concept

For chlorine, the acidic character of its oxides increases with oxidation state:

Cl₂O < Cl₂O₃ < ClO₂ < Cl₂O₇

The higher oxidation state increases the electron-withdrawing character of chlorine and makes the oxide more acidic.

Exam Tip: Higher oxide of a non-metal generally has greater acidic character. Cl₂O₇ is therefore strongly acidic.

Quick Comparison

Na₂O → Basic
Al₂O₃ → Amphoteric
SiO₂ → Acidic
P₂O₅ → Acidic
Cl₂O₇ → Strongly Acidic

30 Related MCQs with Solutions

1. The nature of Cl₂O₇ is:

A. Basic

B. Acidic

C. Amphoteric

D. Neutral

Answer: B. Acidic
It reacts with water to form HClO₄.

2. Cl₂O₇ reacts with water to produce:

A. HCl

B. HClO

C. HClO₃

D. HClO₄

Answer: D. HClO₄

3. The oxidation state of chlorine in Cl₂O₇ is:

A. +1

B. +3

C. +5

D. +7

Answer: D. +7

4. Cl₂O₇ is classified as a:

A. Metallic oxide

B. Non-metal oxide

C. Basic salt

D. Amphoteric hydroxide

Answer: B. Non-metal oxide

5. Which acid is formed by hydration of Cl₂O₇?

A. HClO

B. HClO₂

C. HClO₃

D. HClO₄

Answer: D

6. The reaction Cl₂O₇ + H₂O gives:

A. 2HCl

B. 2HClO

C. 2HClO₃

D. 2HClO₄

Answer: D

7. Which is the highest oxide of chlorine?

A. Cl₂O

B. Cl₂O₃

C. ClO₂

D. Cl₂O₇

Answer: D. Cl₂O₇

8. Which oxide is strongly acidic?

A. Na₂O

B. MgO

C. Cl₂O₇

D. CaO

Answer: C

9. Which oxide is basic?

A. Cl₂O₇

B. SO₃

C. Na₂O

D. P₂O₅

Answer: C. Na₂O

10. Which oxide is amphoteric?

A. Na₂O

B. Al₂O₃

C. SO₃

D. Cl₂O₇

Answer: B. Al₂O₃

11. Acidic character of non-metal oxides generally increases with:

A. Decreasing oxidation state

B. Increasing oxidation state

C. Increasing metallic character

D. Increasing basicity

Answer: B

12. Which chlorine oxide corresponds to HClO₄?

A. Cl₂O

B. Cl₂O₃

C. ClO₂

D. Cl₂O₇

Answer: D

13. HClO₄ is known as:

A. Hypochlorous acid

B. Chlorous acid

C. Chloric acid

D. Perchloric acid

Answer: D. Perchloric acid

14. The central element in Cl₂O₇ is:

A. Oxygen

B. Chlorine

C. Hydrogen

D. None

Answer: B. Chlorine

15. Cl₂O₇ is the anhydride of:

A. HCl

B. HClO

C. HClO₃

D. HClO₄

Answer: D. HClO₄

16. The nature of SO₃ is:

A. Basic

B. Acidic

C. Amphoteric

D. Neutral

Answer: B. Acidic

17. Which oxide is a basic oxide?

A. K₂O

B. SO₃

C. Cl₂O₇

D. CO₂

Answer: A. K₂O

18. Which oxide is acidic in nature?

A. CaO

B. MgO

C. P₂O₅

D. Na₂O

Answer: C

19. Cl₂O₇ + H₂O → ?

A. 2HCl

B. HClO₃

C. 2HClO₄

D. Cl₂ + O₂

Answer: C. 2HClO₄

20. The oxidation state of oxygen in ordinary oxides is generally:

A. +2

B. −2

C. +1

D. −1

Answer: B. −2

21. Which has the highest oxidation state of chlorine?

A. HCl

B. HClO

C. HClO₃

D. HClO₄

Answer: D. HClO₄

22. The acidic character of chlorine oxides generally becomes stronger when chlorine oxidation state:

A. Decreases

B. Increases

C. Remains unchanged

D. Becomes zero

Answer: B

23. Which is a non-metal oxide?

A. Na₂O

B. CaO

C. Cl₂O₇

D. BaO

Answer: C

24. Which oxide is the anhydride of perchloric acid?

A. Cl₂O

B. Cl₂O₃

C. ClO₂

D. Cl₂O₇

Answer: D

25. Which pair contains only acidic oxides?

A. Na₂O, K₂O

B. SO₃, Cl₂O₇

C. CaO, MgO

D. Na₂O, Al₂O₃

Answer: B

26. Which oxide gives a strong acid on reaction with water?

A. Na₂O

B. CaO

C. Cl₂O₇

D. MgO

Answer: C

27. Cl₂O₇ is best described as:

A. Basic anhydride

B. Acidic anhydride

C. Amphoteric oxide

D. Neutral oxide

Answer: B. Acidic anhydride

28. Which oxide corresponds to chlorine in oxidation state +7?

A. Cl₂O

B. Cl₂O₃

C. ClO₂

D. Cl₂O₇

Answer: D

29. Which statement is correct for Cl₂O₇?

A. It forms a base with water

B. It forms HClO₄ with water

C. It is a metallic oxide

D. It is amphoteric

Answer: B

30. The best classification of Cl₂O₇ for competitive exams is:

A. Basic oxide

B. Amphoteric oxide

C. Acidic oxide

D. Neutral oxide

Answer: C. Acidic oxide

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