Final answer:
In the reaction HIO₃ + H₂O = H₃O+ + IO₃-, the Brønsted acid is HIO₃, as it donates a proton to H₂O.
Step-by-step explanation:
The Brønsted acid in the reaction HIO₃ + H₂O = H₃O+ + IO₃- is HIO₃ (iodic acid). In Brønsted-Lowry acid-base theory, an acid is defined as a proton donor. In this reaction, HIO₃ donates a proton to H₂O, forming H₃O+ (the hydronium ion) and IO₃- (the iodate ion). Thus, HIO₃ is the acid because it donates a proton, and H₂O acts as the base because it accepts a proton.
In the chemical equation HIO₃ + H₂O → H₃O⁺ + IO₃⁻, the Brønsted acid is HIO₃. This is because it donates a proton (H⁺) to water (H₂O) to form the hydronium ion (H₃O⁺). The Brønsted base is H₂O, as it accepts the proton from HIO₃ to form the hydroxide ion (OH⁻).