According to the Brønsted–Lowry definition, what is the conjugate acid of $H_{2}O$?

• A. $O{2}^{-}$
• B. $H_2$
• C. $O{-}^{}H$
• D. $H_{3}O+$

Answer: (D)

Verified step by step guidance

1. Recall the Brønsted–Lowry acid-base theory, which defines an acid as a proton (H⁺) donor and a base as a proton acceptor.
2. Identify the species given: water (H₂O) can act as a base by accepting a proton (H⁺).
3. Determine the conjugate acid of H₂O by adding a proton (H⁺) to it, since the conjugate acid is formed when a base gains a proton.
4. Write the chemical formula for the conjugate acid formed by protonating H₂O, which is H₃O⁺ (hydronium ion).
5. Conclude that according to the Brønsted–Lowry definition, the conjugate acid of H₂O is H₃O⁺.