This document discusses acid-base reactions and concepts including: - Conjugate acids and bases are the species that remain after an acid donates or a base accepts a proton. - Stronger acids have weaker conjugate bases, and stronger bases have weaker conjugate acids. Reactions favor production of weaker acid/base pairs. - Amphoteric compounds can act as both acids and bases, such as water and ammonia. - Hydroxyl groups can make compounds acidic, basic, or amphoteric depending on other factors like electronegativity. - Strong acid-strong base neutralization involves complete ionization to hydronium and hydroxide ions which then neutralize to form water.

1. Acid-base reactions Chapter 15.3

2. Conjugate acids and bases Conjugate base Species that remains after a Bronsted-Lowry acid has given up a proton Conjugate acid Species that remains after a Bronsted-Lowry base gains a proton HF + H2O H3O+ + F- HF + H2O H3O+ + F- acid Conjugate base base Conjugate acid

3. Strength of Conjugate Acids and Bases The stronger the acid, the weaker it’s conjugate base The stronger the base, the weaker it’s conjugate acid Proton-transfer reactions favor the PRODUCTION of weaker acids and bases. HCl + H2O H3O+ + Cl- HF + H2O H3O+ + F- Strong acid weak base weaker acid stronger base weaker base stronger acid

4. Amphoteric Compounds Any species that can react as either an acid or a base H2SO4 + H2O H3O+ + HSO4- NH3 + H2O NH4+ + OH- H2O is amphoteric acid base base acid acid base acid base

5. -OH in a molecule -OH hydroxyl group Molecular compound with –OH Can be acidic or amphoteric More electronegative form compounds with acidic hydroxyl groups Basic amphoteric acidic Cr(OH)2 Cr(OH)3 H2CrO4 The more oxygen, the more acidic

7. Sodium Hydroxide dissociates in water

8. NaOH(aq) Na+ (aq) + OH- (aq)

9. Hydrochloric Acid ionizes in water

10. HCl (aq) + H2O (l) H3O+(aq) + Cl- (aq)

11. When the two are mixed:

12. H3O+(aq) + Cl- (aq) + Na+ (aq) + OH- (aq) Na+ (aq) + Cl- (aq) + H2O (l) Net ionic equation: H3O+(aq) + OH- (aq) H2O (l) Neutralization – reaction of hydronium ions and hydroxide ions to form water molecules Salt – ionic compound composed of a cation from a base and an anion from an acid.

13. Acid Rain Industrial Processes Produce – NO, NO2, CO2, SO2, SO3 SO3 (g) + H2O (l) H2SO4 (aq) atmosphere rain acid rain