Among the following oxides, which has the maximum lattice energy?

Options

A. MgO
B. CaO
C. SrO
D. BaO

Answer

To determine which oxide has the maximum lattice energy among magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO), we can follow these steps:

### Step 1: Understand Lattice Energy
Lattice energy is the amount of energy released when one mole of an ionic solid is formed from its gaseous ions. It is influenced by two main factors: the charge of the ions and the size of the ions.

### Step 2: Analyze the Factors Affecting Lattice Energy
- **Charge of the Ions**: Lattice energy is directly proportional to the charge of the ions. Higher charges lead to stronger electrostatic forces and thus higher lattice energy.
- **Size of the Ions**: Lattice energy is inversely proportional to the size of the ions. Smaller ions can get closer together, leading to stronger attractions and higher lattice energy.

### Step 3: Compare the Oxides
1. **Magnesium Oxide (MgO)**: Contains Mg²⁺ and O²⁻ ions. Mg²⁺ has a relatively small size.
2. **Calcium Oxide (CaO)**: Contains Ca²⁺ and O²⁻ ions. Ca²⁺ is larger than Mg²⁺.
3. **Strontium Oxide (SrO)**: Contains Sr²⁺ and O²⁻ ions. Sr²⁺ is larger than Ca²⁺.
4. **Barium Oxide (BaO)**: Contains Ba²⁺ and O²⁻ ions. Ba²⁺ is the largest among these cations.

### Step 4: Determine the Order of Lattice Energy
- Since Mg²⁺ is the smallest cation and has a high charge, it will have the highest lattice energy.
- As we move down the group from Mg to Ba, the size of the cation increases, leading to a decrease in lattice energy.

### Conclusion
Based on the analysis, magnesium oxide (MgO) has the maximum lattice energy among the given options.

### Final Answer
**The oxide with the maximum lattice energy is Magnesium Oxide (MgO).**

---