Answer
$MgCl_2$ has higher magnitude lattice energy
Work Step by Step
$NaCl$ has low magnitude lattice energy because magnitude of charge on ions is 1. $MgCl_2$ has higher magnitude lattice energy because magnitude of charge on ions is 2.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.