Que no 82

Dear User,

Lattice energy depends upon charge as well as size of ions. In case of Al₂O₃, CaO, MgBr₂ and NaCl, decreasing order of charge on cations is : 
Al³⁺>Ca²⁺=Mg²⁺>Na+
Decreasing order of charge on anion :
O^2->Cl^​-=Br^-
 As the charge of the ions increases, the lattice energyincreases. as the size of the ions increases, the lattice energy decreases 
Therefore, the decreasing order of Lattice energy comes out to be 
Al₂O₃>CaO>MgBr₂>NaCl

Regards
 

---