Lattice energy in sodium chloride is y kJ. Assuming the same interionic distance, what will be the lattice energy of magnesium sulphide ?

Explanation

To find the lattice energy of magnesium sulfide (MgS) given the lattice energy of sodium chloride (NaCl) is \( Y \) kJ, we can follow these steps:

### Step 1: Understand the concept of lattice energy
Lattice energy is the energy required to separate one mole of a solid ionic compound into its gaseous ions. For NaCl, the lattice energy is given as \( Y \) kJ.

### Step 2: Write the lattice energy formula
The lattice energy \( U \) can be expressed as:
\[
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