This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.
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Step 1: Lewis structure for the sulfite ion SO_3^2-. Total valence electrons: S contributes 6, 3 × O contribute 3 × 6 = 18, +2 electrons from charge = 6 + 18 + 2 = 26 electrons. Place S in center bonded to 3 O atoms with single bonds (3 bonds = 6 electrons used). Distribute remaining electrons: each O gets 3 lone pairs (3 × 6 = 18 electrons), S gets 1 lone pair (2 electrons). Total: 6 + 18 + 2 = 26. Formal charges: S: 6 - 2 - (6)/(2) = +1; each terminal O: 6 - 6 - (2)/(2) = -1. To minimize formal charges, convert one S–O single bond to double bond. Double-bonded O: 2 lone pairs (4 electrons), FC = 6 - 4 - (4)/(2) = 0. Single-bonded O: FC = -1 each. S: FC = 6 - 2 - (8)/(2) = 0. One resonance structure: [\, ^-O-S(=O)-O^- \,]^2- (with lone pairs on O atoms, S has 1 lone pair). Resonance delocalizes the double bond among 3 positions. Step 2: Definition of Lewis acid. A Lewis acid is a species that accepts an electron pair to form a coordinate covalent bond. Examples: HCl, H_2SO_4, BF_3. Step 3: Definition of Lewis base. A Lewis base is a species that donates an electron pair to form a coordinate covalent bond. Examples: NH_3, OH^-. Step 4: Common Lewis acids and bases. c|c Lewis acid & Lewis base \\ HCl & NH_3 \\ H_2SO_4 & OH^- \\ BF_3 & H_2O Step 5: Formula for the conjugate base of HSO_3^-. HSO_3^- H^+ + SO_3^2- Conjugate base: SO_3^2-. Step 6: Formula for the conjugate base of HSO_4^-. HSO_4^- H^+ + SO_4^2- Conjugate base: SO_4^2-. Step 7: Formula for the conjugate acid of SO_3^2-. SO_3^2- + H^+ HSO_3^- Conjugate acid: HSO_3^-. Step 8: Formula for the conjugate acid of SO_4^2-. SO_4^2- + H^+ HSO_4^- Conjugate acid: HSO_4^-. Step 9: Amphiprotic substances. Amphiprotic (amphoteric in Brønsted-Lowry sense) substances act as both acids (donate H^+) and bases (accept H^+). HSO_3^-: As acid: HSO_3^- H^+ + SO_3^2- As base: HSO_3^- + H^+ H_2SO_3 HSO_4^-: As acid: HSO_4^- H^+ + SO_4^2- As base: HSO_4^- + H^+ H_2SO_4 Step 10: Verify different acid strengths (of HSO_3^- and HSO_4^-). HSO_4^- is the stronger acid (pK_a ≈ 1.9) compared to HSO_3^- (pK_a ≈ 7.2), as SO_4^2- is a weaker base than SO_3^2- due to higher oxidation state of S (+6 vs. +4) and more resonance stabilization. HSO_4^- is stronger acid than HSO_3^-.