Amphoteric oxides among: BeO,SnO 2 ​ ,ZnO,Al 2 ​ O 3 ​ .

1. Amphoteric oxides among: BeO, SnO₂, ZnO, Al₂O₃. +

Correct Answer

BeO, SnO₂, ZnO and Al₂O₃
All four are amphoteric oxides.

What is an Amphoteric Oxide?

An amphoteric oxide is an oxide that can react with both acids and bases to form salts.

Amphoteric oxide + Acid → Salt + Water

Amphoteric oxide + Base → Salt/Complex + Water

The given oxides are:

BeO   |   SnO₂   |   ZnO   |   Al₂O₃

All four exhibit amphoteric behaviour.

1. Beryllium Oxide — BeO

BeO reacts with acids:

BeO + 2HCl → BeCl₂ + H₂O

It also reacts with strong bases such as NaOH:

BeO + 2NaOH + H₂O → Na₂[Be(OH)₄]

Therefore, BeO is amphoteric.

2. Tin(IV) Oxide — SnO₂

SnO₂ reacts with acids:

SnO₂ + 4HCl → SnCl₄ + 2H₂O

It also reacts with strong bases to form stannate species:

SnO₂ + 2NaOH → Na₂SnO₃ + H₂O

Hence, SnO₂ is amphoteric.

3. Zinc Oxide — ZnO

With acid:

ZnO + 2HCl → ZnCl₂ + H₂O

With base:

ZnO + 2NaOH + H₂O → Na₂[Zn(OH)₄]

Therefore, ZnO is amphoteric.

4. Aluminium Oxide — Al₂O₃

With acid:

Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

With base:

Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄]

Thus, Al₂O₃ is also amphoteric.

JEE / NEET Shortcut

BeO + ZnO + Al₂O₃ + SnO₂ = Amphoteric

Important common amphoteric oxides to remember:

BeO, Al₂O₃, ZnO, SnO, SnO₂, PbO, PbO₂

A particularly important exam pair is: BeO and Al₂O₃, which also demonstrates the diagonal relationship between Be and Al.

30 Related MCQs with Solutions

1. Which of the following is amphoteric?

A. Na₂O

B. MgO

C. ZnO

D. K₂O

Answer: C. ZnO

2. Which set contains only amphoteric oxides?

A. BeO, ZnO, Al₂O₃

B. Na₂O, K₂O, CaO

C. CO₂, SO₂, SO₃

D. Na₂O, Al₂O₃, CO₂

Answer: A

3. BeO reacts with both:

A. Only acids

B. Only bases

C. Acids and bases

D. Neither

Answer: C

4. Which oxide is amphoteric?

A. Al₂O₃

B. Na₂O

C. K₂O

D. CaO

Answer: A. Al₂O₃

5. Which oxide reacts with NaOH to form a soluble complex?

A. ZnO

B. Na₂O

C. K₂O

D. CaO

Answer: A. ZnO

6. Which oxide is amphoteric?

A. SnO₂

B. SO₃

C. CO₂

D. P₂O₅

Answer: A. SnO₂

7. Amphoteric oxides can react with:

A. Acids only

B. Bases only

C. Both acids and bases

D. Water only

Answer: C

8. Which is NOT amphoteric?

A. BeO

B. ZnO

C. Al₂O₃

D. Na₂O

Answer: D. Na₂O

9. The oxide of aluminium is:

A. Acidic

B. Basic

C. Amphoteric

D. Neutral

Answer: C. Amphoteric

10. The oxide of beryllium is:

A. Strongly acidic

B. Amphoteric

C. Strongly basic

D. Neutral

Answer: B. Amphoteric

11. Which oxide is amphoteric among the following?

A. MgO

B. ZnO

C. Na₂O

D. K₂O

Answer: B. ZnO

12. Which oxide is commonly used as an example of amphoterism?

A. ZnO

B. Na₂O

C. CO₂

D. SO₂

Answer: A. ZnO

13. Which pair shows diagonal relationship through amphoteric oxides?

A. Be–Al

B. Li–Na

C. Na–K

D. F–Cl

Answer: A. Be–Al

14. Al₂O₃ reacts with NaOH to form:

A. NaCl

B. Sodium aluminate/hydroxoaluminate species

C. Na₂O

D. AlCl₃

Answer: B

15. ZnO reacts with HCl to form:

A. ZnCl₂

B. Zn(OH)₂

C. Na₂ZnO₂

D. ZnCO₃

Answer: A. ZnCl₂

16. SnO₂ is:

A. Acidic only

B. Basic only

C. Amphoteric

D. Neutral only

Answer: C. Amphoteric

17. Which oxide reacts with both HCl and NaOH?

A. ZnO

B. Na₂O

C. K₂O

D. CaO

Answer: A. ZnO

18. Which combination contains four amphoteric oxides?

A. BeO, SnO₂, ZnO, Al₂O₃

B. Na₂O, K₂O, CaO, MgO

C. CO₂, SO₂, SO₃, P₂O₅

D. Na₂O, CO₂, SO₃, K₂O

Answer: A

19. Amphoteric behaviour means the oxide can behave as:

A. Only an acid

B. Only a base

C. Both acid and base

D. Only a salt

Answer: C

20. Which oxide is basic rather than amphoteric?

A. ZnO

B. BeO

C. Na₂O

D. Al₂O₃

Answer: C. Na₂O

21. Which oxide is acidic?

A. Na₂O

B. MgO

C. CO₂

D. ZnO

Answer: C. CO₂

22. Which oxide is amphoteric in Group 13?

A. B₂O₃

B. Al₂O₃

C. Tl₂O

D. Na₂O

Answer: B. Al₂O₃

23. Which oxide is amphoteric in Group 12?

A. ZnO

B. Na₂O

C. K₂O

D. BaO

Answer: A. ZnO

24. Which oxide shows amphoteric behaviour due to high charge density of the metal ion?

A. BeO

B. K₂O

C. Na₂O

D. Cs₂O

Answer: A. BeO

25. Which is the correct classification?

A. BeO — amphoteric

B. Na₂O — amphoteric

C. CO₂ — basic

D. K₂O — amphoteric

Answer: A

26. Which oxide reacts with both acid and alkali?

A. Al₂O₃

B. Na₂O

C. K₂O

D. CaO

Answer: A. Al₂O₃

27. Which of the following is NOT an amphoteric oxide?

A. ZnO

B. BeO

C. Al₂O₃

D. SO₃

Answer: D. SO₃

28. The basic reaction of ZnO with NaOH demonstrates its:

A. Acidic nature

B. Amphoteric nature

C. Neutral nature

D. Metallic nature

Answer: B. Amphoteric nature

29. Which set is correctly matched?

A. BeO — Amphoteric

B. ZnO — Amphoteric

C. Al₂O₃ — Amphoteric

D. All of these

Answer: D. All of these

30. The correct answer to the original question is:

A. BeO only

B. ZnO and Al₂O₃ only

C. BeO, SnO₂, ZnO and Al₂O₃

D. None

Answer: C. All four are amphoteric.

Advertisement