The binary compounds of oxygen with other elements are called oxides. They are classified depending either upon their acid-base characteristics or on the basis of oxygen content.
(a) Normal oxides : These oxides which contain oxygen atom as permitted by the normal oxidation number, i.e., `-2` normal oxide may be acidic, basic, amphoteric or neutral.
(b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of `-2`.
(i) Peroxides : Two oxygen atoms are linked to each other and oxyegen has `-1` oxidation number. They contain `(O -O)^(2-)` unit.
(ii) Superoxodes : These oxides contain `(O-O)^(-1)` unit, i.e., each O-atom has oxidation number `-1//2`.
(c) Suboxides : These contain low content of oxygen than expected.
(d) Mixed oxides : These oxides are made of two simpler oxides.
Which of the following pairs contains amphoteric oxides ?

Options

A. `BeO, BaO`
B. `BeO, Al_2 O_3`
C. `Al_2 O_3, P_2 O_5`
D. `FeO, CuO`

Answer

To determine which pair contains amphoteric oxides, we need to understand the properties of amphoteric oxides. Amphoteric oxides can react with both acids and bases, exhibiting both acidic and basic characteristics.

### Step-by-Step Solution:

1. **Understand the Definition of Amphoteric Oxides**:
- Amphoteric oxides are those that can react with both acids and bases. This means they can behave as either an acid or a base depending on the reaction conditions.

2. **Examine the Given Options**:
- We need to analyze each option provided to identify which oxides are amphoteric.

3. **Option Analysis**:
- **Option A: Barium Oxide (BaO) and Phosphorus Pentoxide (P2O5)**:
- Barium oxide is a basic oxide, while phosphorus pentoxide is acidic. This pair does not contain amphoteric oxides.

- **Option B: Beryllium Oxide (BeO) and Aluminum Oxide (Al2O3)**:
- Both beryllium oxide and aluminum oxide are known to exhibit amphoteric behavior. They can react with acids and bases, making this pair a valid option.

- **Option C: Magnesium Oxide (MgO) and Zinc Oxide (ZnO)**:
- Magnesium oxide is primarily basic, and zinc oxide is amphoteric but not basic. Therefore, this pair does not contain two amphoteric oxides.

- **Option D: Lead Oxide (PbO) and Tin Oxide (SnO)**:
- Lead oxide can be basic or amphoteric, and tin oxide is amphoteric. However, since lead oxide is not consistently amphoteric, this pair is not a strong candidate.

4. **Conclusion**:
- After analyzing all the options, the only pair that contains amphoteric oxides is **Option B: Beryllium Oxide (BeO) and Aluminum Oxide (Al2O3)**.

### Final Answer:
The pair that contains amphoteric oxides is **Option B: Beryllium Oxide (BeO) and Aluminum Oxide (Al2O3)**.

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