Answer:
a. H₂O (conjugate acid); b. OH⁻ (conjugate base), H₃O⁺ (conjugate acid); c. H₂CO₃ (conjugate acid), CO₃⁻² (conjugate base); d. NH₄⁺ (conjugate strong acid) e. H₂SO₄ (conjugate acid), SO₄⁻² (conjugate base); f. No conjugate acid or base exists; g. H₂S (conjugate acid), S⁻² (conjugate base);
h. H₄N₂ (conjugate base)
Explanation:
a. OH⁻ + H⁺ ⇄ H₂O
The hydroxide functions as a Bronsted-Lowry base, allowing it to capture a proton, thus water serves as the conjugate acid.
b. H₂O is amphoteric, capable of acting as either an acid or a base. As a base, its conjugate acid is H₃O⁺, whereas as an acid, its conjugate base is OH⁻.
c. HCO₃⁻ + H⁺ ⇄ H₂CO₃
HCO₃⁻ + H₂O ⇄ CO₃⁻² + H₃O⁺
Bicarbonate is also amphoteric. When it captures a proton, it forms carbonic acid as the conjugate acid when acting as a base. When HCO₃⁻ acts as an acid and releases a proton, carbonate becomes the conjugate base.
d. Ammonia functions as a weak base, with ammonium being the conjugate strong acid.
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
e. Another amphoteric compound. Acid sulfate can function as both an acid and a base.
(similar to bicarbonate). Acting as a base yields sulfuric acid as the conjugate acid, while acting as an acid leads to sulfate as the conjugate base.
HSO₄⁻ + H₂O ⇄ SO₄⁻² + H₃O⁺
HSO₄⁻ + H⁺ ⇄ H₂SO₄
f. H₂O₂ does not accept H⁺ or OH⁻ nor does it expel H⁺. It’s neutral and does not function as an acid or base.
g. HS⁻ is amphoteric.
HS⁻ + H⁺ ⇄ H₂S
HS⁻ + H₂O ⇄ S⁻² + H₃O⁺
This is similar to the case of bicarbonate or acid sulfate.
h. H₅N₂⁺ + H₂O ⇄ H₄N₂ + H₃O⁺
Hydrazinium acts as an acid, making hydrazine its conjugate base.
