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

Explanation

The charge magnitudes of ions in NaCl are 1 and 1 respectively. The product of `q_1` and `q_2 = 1 xx 1 = 1`
The charge magnitudes of ions in magnesium sulphide are 2 and 2 respectively.
The product of `q_1` and `q_2 = 2 xx 2 = 4`
Hence lattice energy of MgS `= 4 xx kJ.`