Among the following metal oxides, which is most basic?

Options

A. `ZnO`
B. `Al_(2)O_(3)`
C. `As_(2)O_(3)`
D. `K_(2)O`

Answer

To determine which of the given metal oxides is the most basic, we can analyze each oxide based on its chemical properties.

### Step-by-Step Solution:

1. **Identify the Metal Oxides**: The metal oxides mentioned are ZnO (zinc oxide), Al2O3 (aluminum oxide), H2AsO3 (arsenic trioxide), and K2O (potassium oxide).

2. **Classify Each Oxide**:
- **ZnO (Zinc Oxide)**: This oxide is amphoteric, meaning it can react with both acids and bases. It can act as a base when reacting with acids and as an acid when reacting with strong bases.
- **Al2O3 (Aluminum Oxide)**: Similar to ZnO, Al2O3 is also amphoteric. It can react with acids and bases.
- **H2AsO3 (Arsenic Trioxide)**: This oxide is classified as an acidic oxide. Acidic oxides typically react with bases and do not exhibit basic properties.
- **K2O (Potassium Oxide)**: This oxide is a basic oxide. It reacts with water to form potassium hydroxide (KOH), which is a strong base.

3. **Compare Basicity**:
- Since ZnO and Al2O3 are amphoteric, they can exhibit both acidic and basic characteristics but are not as strongly basic as K2O.
- H2AsO3 is acidic and does not contribute to basicity.
- K2O is a basic oxide and is known for its strong basic properties.

4. **Conclusion**: Among the given options, K2O (potassium oxide) is the most basic metal oxide.

### Final Answer:
K2O is the most basic among the given metal oxides.

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