Final answer:
The anhydride of selenic acid (H₂SeO₄) is selenium trioxide (SeO₃), resembling the behavior of sulfuric acid forming its anhydride, SO₃. Option 3
Step-by-step explanation:
The anhydride of selenic acid (H₂SeO₄) corresponds to the nonmetallic selenium oxide that would form upon the removal of water (dehydration) from the acid. Selenic acid is similar to sulfuric acid (H₂SO₄), which is a diprotic acid known to form sulfur trioxide (SO₃) as its anhydride.
Analogously, the anhydride of selenic acid is selenium trioxide (SeO₃), which would form upon the acid losing its water (two molecules of water from two molecules of acid), leaving SeO₃ as the oxide. Option 3