In this reaction NH4+ + H2O -----> H3O+, the conjugate base of H3O+ ion is:
Correct answer: B. H2O
- A. NH4+
- B. H2O
- C. H+
- D. NH3
Explanation
In the Brønsted-Lowry definition of acids and bases, a conjugate acid-base pair consists of two substances that differ only by the presence of a proton (H⁺). A conjugate acid is formed when a proton is added to a base, and a conjugate base is formed when a proton is removed from an acid. In this reaction H2O is accepting an H+ to form H3O+, hence it is the conjugate base of H3O+.
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About Acids, Bases and Salts
Acid and base behaviour is explained through the Bronsted-Lowry transfer of protons and the Lewis donation or acceptance of electron pairs. The topic includes pH, pOH, ionisation and water equilibrium, plus salt formation and hydrolysis, where a salt solution may become acidic, basic or neutral.
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