Let’s go step by step through each reaction. Remember:
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Acid = gives away H⁺ (proton donor)
-
Base = picks up H⁺ (proton acceptor)
-
Conjugate Acid = what the base becomes after picking up H⁺
-
Conjugate Base = what the acid becomes after giving away H⁺
We’ll label each part for reactions 2 to 5. Reaction 1 is already done as an example.
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Reaction 2: H₂SO₄ + OH⁻ ↔ HSO₄⁻ + H₂O
Step 1: Who gives H⁺? → H₂SO₄ loses one H⁺ to become HSO₄⁻ → so H₂SO₄ is the
acid
Step 2: Who takes H⁺? → OH⁻ gains H⁺ to become H₂O → so OH⁻ is the
base
Step 3: What does the acid turn into? → HSO₄⁻ → that’s the
conjugate base
Step 4: What does the base turn into? → H₂O → that’s the
conjugate acid
✔ Labels:
- H₂SO₄ → Acid
- OH⁻ → Base
- HSO₄⁻ → C. Base
- H₂O → C. Acid
*(Note: The original worksheet says “H₂O⁺” — that’s a typo! It should be H₂O. We’ll use H₂O.)*
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Reaction 3: HSO₄⁻ + H₂O ↔ SO₄²⁻ + H₃O⁺
Step 1: Who gives H⁺? → HSO₄⁻ loses H⁺ to become SO₄²⁻ → so HSO₄⁻ is the
acid
Step 2: Who takes H⁺? → H₂O gains H⁺ to become H₃O⁺ → so H₂O is the
base
Step 3: Conjugate base of HSO₄⁻ → SO₄²⁻
Step 4: Conjugate acid of H₂O → H₃O⁺
✔ Labels:
- HSO₄⁻ → Acid
- H₂O → Base
- SO₄²⁻ → C. Base
- H₃O⁺ → C. Acid
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Reaction 4: OH⁻ + HO⁺ ↔ H₂O + H₂O
Step 1: Who gives H⁺? → H₃O⁺ loses H⁺ to become H₂O → so H₃O⁺ is the
acid
Step 2: Who takes H⁺? → OH⁻ gains H⁺ to become H₂O → so OH⁻ is the
base
Step 3: Conjugate base of H₃O⁺ → H₂O
Step 4: Conjugate acid of OH⁻ → H₂O
✔ Labels:
- OH⁻ → Base
- H₃O⁺ → Acid
- First H₂O (from OH⁻) → C. Acid
- Second H₂O (from H₃O⁺) → C. Base
*(Both products are water, but we label them based on where they came from.)*
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Reaction 5: NH₃ + H₂O ↔ NH₄⁺ + OH⁻
Step 1: Who gives H⁺? → H₂O loses H⁺ to become OH⁻ → so H₂O is the
acid
Step 2: Who takes H⁺? → NH₃ gains H⁺ to become NH₄⁺ → so NH₃ is the
base
Step 3: Conjugate base of H₂O → OH⁻
Step 4: Conjugate acid of NH₃ → NH₄⁺
✔ Labels:
- NH₃ → Base
- H₂O → Acid
- NH₄⁺ → C. Acid
- OH⁻ → C. Base
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Final Answer:
2. H₂SO₄ → Acid; OH⁻ → Base; HSO₄⁻ → C. Base; H₂O → C. Acid
3. HSO₄⁻ → Acid; H₂O → Base; SO₄²⁻ → C. Base; H₃O⁺ → C. Acid
4. OH⁻ → Base; H₃O⁺ → Acid; H₂O (from OH⁻) → C. Acid; H₂O (from H₃O⁺) → C. Base
5. NH₃ → Base; H₂O → Acid; NH₄⁺ → C. Acid; OH⁻ → C. Base
Parent Tip: Review the logic above to help your child master the concept of bronsted lowry acids and bases worksheet.
