1. Smaller ionic size:
* Sodium (Na+) is smaller than potassium (K+) and bromide (Br-) is larger than chlorine (Cl-).
* Smaller ions attract each other more strongly due to the closer proximity of their charges.
* This stronger electrostatic attraction leads to higher lattice energy.
2. Higher charge density:
* Sodium (Na+) has a higher charge density compared to potassium (K+) because it has the same charge but smaller size.
* Higher charge density means a stronger attraction between the ions, contributing to higher lattice energy.
3. Greater electronegativity difference:
* The electronegativity difference between sodium (Na) and chlorine (Cl) is larger than between potassium (K) and chlorine (Cl) or potassium (K) and bromine (Br).
* Greater electronegativity difference means a more ionic character in the bond, leading to stronger electrostatic attraction and higher lattice energy.
In summary:
The combination of smaller ionic size, higher charge density, and greater electronegativity difference in NaCl results in stronger electrostatic interactions and a higher lattice energy compared to KCl and KBr.
