Question

What’s the amount of lattice energy of NaCl?

(a) 788 KJ mol^-1

(b) 688 KJ mol^-1

(c) 588 KJ mol^-1

(d) 488 KJ mol^-1

The question was asked by my college director while I was bunking the class.

I need to ask this question from Ionic or Electrovalent Bond in division Chemical Bonding and Molecular Structure of Chemistry – Class 11

Answer 1

Correct answer is (a) 788 KJ mol^-1

To elaborate: NaCl’s lattice enthalpy is given by 788 KJ mol^-1. To disassociate one mole of NaCl into one mole of Na^+ and one mole of Cl^-1 into an infinite distance, we need 788 KJ mol^-1 of energy. When the ions are combined to form an ionic compound that is a crystalline solid, a certain amount of energy is released and this is known as the lattice energy.