Which of the following order is correct ? — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Lattice energy (U) is directly proportional to the product of ionic charges (q1 * q2) and inversely proportional to the interionic distance (r). Step 2: (i) MgO (+2/-2 charges) has a much higher lattice energy than KCl (+1/-1 charges). (ii) LiF has smaller ions (F- < Br-) than LiBr, giving it higher lattice energy. (iii) Mg3N2 (+2/-3 charges) has significantly higher charges and smaller radii than NaCl (+1/-1 charges). Step 3: The compounds with higher lattice energy are MgO, LiF, and Mg3N2, matching option (d).