Final answer:
NaCl, or sodium chloride, is the univalent ionic compound among the given options, consisting of singly charged Na+ and Cl- ions. The option (A) is correct.
Step-by-step explanation:
The univalent ionic compound among the options NaCl, H₂O, CH₄, HCl, FeSO₄ is NaCl (sodium chloride). A univalent (or monovalent) ionic compound contains ions that are singly charged, which means they either have lost one electron (cation) or gained one electron (anion).
Sodium chloride is composed of Na+ and Cl− ions, each with a single positive or negative charge, respectively, making it a univalent ionic compound. Therefore, option (A) is correct.