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Acids And Bases

Acids And Bases. Where can acids be found? Sodas Stomach Vinegar Citrus fruits. Where can bases be found? Soap Drano Antacid tablets Windex detergent. Class question. Properties of Acids. Taste sour React with bases Litmus paper test – turn blue litmus paper red

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Acids And Bases

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  1. Acids AndBases

  2. Where can acids be found? Sodas Stomach Vinegar Citrus fruits Where can bases be found? Soap Drano Antacid tablets Windex detergent Class question

  3. Properties of Acids • Taste sour • React with bases • Litmus paper test – turn blue litmus paper red • Electrolytic – conduct electricity

  4. Properties of Bases • Taste bitter • Feels slippery • React with acids • Litmus paper test – turn red litmus paper blue • electrolytic

  5. Nomenclature of Acids • Acids are composed of a(n) ________________ followed by a(n) _______ Hydrogen ion (H+) anion H+ + Cl1- HCl Ex: H+ + SO42- H2SO4

  6. Binary AcidsH+ + anion • H+ + anion with –ide ending  acid name is __________________ HCl anion? _______ acid name ________________ Hydro _____ic acid chloride Hydrochloric acid

  7. Binary AcidsH+ + anion • H+ + anion with –ide ending  acid name is __________________ HF anion? _______ acid name ________________ Hydro _____ic acid fluoride Hydrofluoric acid

  8. OxyacidsH+ + anion • H+ + anion with –ate ending  acid name is __________________ HNO3 anion? _______ acid name ________________ _____ic acid nitrate nitric acid

  9. OxyacidsH+ + anion • H+ + anion with –ate ending  acid name is __________________ H2SO4 anion? _______ acid name ________________ _____ic acid sulfate sulfuric acid

  10. OxyacidsH+ + anion • H+ + anion with –ite ending  acid name is __________________ HNO2 anion? _______ acid name ________________ _____ous acid nitrite nitrous acid

  11. OxyacidsH+ + anion • H+ + anion with –ite ending  acid name is __________________ HClO2 anion? _______ acid name ________________ _____ous acid chlorite chlorous acid

  12. Writing acid formulas • Hydrobromic acid anion? ___________ formula ______ • Acetic acid anion? ___________ formula ______ • Nitrous acid anion? ___________ formula ______ HBr Bromide (Br1-) HC2H3O2 acetate(C2H3O21-) HNO2 nitrite (NO21-)

  13. Nomenclature of Bases • Bases are composed of a(n) _______ followed by a(n) ________________ cation hydroxide (OH1-)

  14. Writing Base Names • Rule: name the cation and add “hydroxide” • NaOH • Mg(OH)2 • Fe(OH)3 sodium hydroxide magnesium hydroxide Iron (III) hydroxide Memorize: NH3 = ammonia

  15. Writing base formulas • potassium hydroxide cation? ______ formula ______ • Calcium hydroxide cation? ______ formula ______ • Aluminum hydroxide cation? ______ formula ______ KOH K+ Ca(OH)2 Ca2+ Al(OH)3 Al3+

  16. Ions In Solution • Why are some solutions acidic, basic, or neutral? It depends on number of H+ and OH- ions present.

  17. Ions In Solution • Acidic solution – contain more H+ ions than OH- ions 4000 H+ and 0 OH- is acidic 1000 H+ and 500 OH- is acidic 5 H+ and 3 OH- is acidic

  18. Ions In Solution • Basic Solution – contain more OH- ions than H+ ions 4000 OH- and 0 H+ is basic 1000 OH- and 500 H+ is basic 5 OH- and 3 H+ is basic

  19. Ions In Solution • Neutral Solution – equal amounts of H+ and OH- ions 4000 OH- and 4000 H+ is neutral 1000 OH- and 1000 H+ is neutral 5 OH- and 5 H+ is neutral

  20. Self Ionization of Water • simplified version H2O → H+ + OH-

  21. Types of Acids/Bases • Arrhenius Model • Bronsted-Lowry Model • Lewis Model

  22. Arrhenius Model of Acids and Bases • Arrhenius Acids • Defn: contain H+ and ionizes to form H+ • Examples HCl  HNO3  makes solution ACIDIC H+ + Cl- H+ + NO3-

  23. Arrhenius Model of Acids and Bases • Arrhenius Bases • Defn: • contain OH- and ionizes to produce OH- ions • Examples NaOH  Ca(OH)2  makes solution BASIC Na+ + OH- Ca2+ + 2 OH-

  24. Bronsted-Lowry Model • Bronsted-Lowry Acid • Defn: proton/H+donor • can give H+ to another species • Bronsted-Lowry Base • Defn: proton/H+acceptor • can take H+ from another species

  25. Bronsted-Lowry Model • REMEMBER!!!! REMEMBER!!!! acids donate, bases accept protons Abigail doesn’t buy apples.

  26. Bronsted-Lowry Model • Examples HCl + H2O  Cl- + H3O+ What is happening here? Acid (donates proton) Base (accepts proton) Which is the acid? base?

  27. Bronsted-Lowry Model • Examples NH3 + H2O  NH4+ + OH- What is happening here? Base (accepts proton) Acid (donates proton) Which is the acid? base?

  28. Lewis Model • Lewis acid • an atom, ion, or molecule that accepts an electron pair to form a covalent bond • Lewis base • An atom, ion, or molecule that donates an electron pair to form a covalent bond

  29. Lewis Model • Lewis acid-base reaction • The formation of one or more covalent bonds between an electron-pair donor and an electron-pair acceptor

  30. Conjugate Acid/Base Pairs • Conjugate acid – new species produced when base gains H+ ion • Conjugate base – new species produced when acid donates H+ ion

  31. Conjugate Acid/Base Pairs • general Bronsted-Lowry reaction acid + base  conj. acid + conj. base conj. acid/base pair conj. acid/base pair Every acid has a conjugate base. Every base has a conjugate acid.

  32. Conjugate Acid/Base Pairs • Examples HNO3 + H2O  H3O+ + NO3- What is the acid? base? conj. acid/base pair C.A. C.B. acid base What is the conjugate acid/base? conj. acid/base pair

  33. Conjugate Acid/Base Pairs • Examples NH3 + H2O  NH4+ + OH- What is the acid? base? conj. acid/base pair base acid C.A. C.B. What is the conjugate acid/base? conj. acid/base pair

  34. Conjugate acid-base pairs • What is the conjugate base of: H2SO4 _________ H3O+ ________ • What is the conjugate acid of: HPO42- _________ OH1- ________ HSO41- H2O H2PO41- H2O How can H2O be both acid and base?

  35. Amphoteric • Defn – substance that can act as both acids and bases HNO3 + H2O  H3O+ + NO3- NH3 + H2O  NH4+ + OH- Is H2O a base or acid? base Is H2O a base or acid? acid Water is amphoteric b/c it is acts as a base in one reaction and acts as an acid in the second

  36. Mono-, Di-, Triprotic Acids • Defns • monoprotic (HA) – one ionizable proton ex: HF, HCl, HBr (= normality is 1) • diprotic (H2A) – two ionizable protons ex: H2SO4, H2CO3 (= normality is 2) • triprotic (H3A) – three ionizable protons ex: H3PO4, H3BO3 (= normality is 3)

  37. Polyprotic Acid Ionization • Always forms ONE H+ H3PO4 H2PO41- HPO42- H2PO41- + H+ HPO42- + H+ PO43- + H+

  38. Strong Acid/Base • Defn – acid or base that completely ionizes HA H+ + A- XOH X+ + OH- 100% ionization 100% ionization • every single HA molecule ionizes into H+ and A-

  39. Strong Acid • Illustration + + - H H A A + + - H H A A + + - H H A A All break into ions

  40. 6 Strong Acids • HCl – hydrochloric acid • HBr – hydrobromic acid • HI – hydroiodic acid • HClO4 – perchloric acid • H2SO4 – sulfuric acid • HNO3 – nitric acid

  41. Strong Bases • Group I and II metal hydroxides LiOH NaOH KOH RbOH Mg(OH)2 Ca(OH)2 Sr(OH)2 Ba(OH)2 No need to memorize exact ones

  42. Weak Acid/Base • Defn – acid or base that partially ionizes HA H+ + A- XOH X+ + OH- partial ionization • not all will ionize;the weaker it is the less it ionizes

  43. Weak Acid • Illustration + + - H H A A H H A A H H A A Only some break into ions

  44. What are the weak acids and bases? • The ones that are NOT strong

  45. Strong or weak, concentrated or diluted • For acids and bases, it is important to distinguish between concentrated and dilute from strong and weak. The words _________ and __________ have different meanings. Similarly, ___________ and ___________ are not the same either. strong concentrated weak dilute

  46. Strong or weak, concentrated or diluted • Strong and weak refer to ____________________________ • Concentrated and dilute refer to ____________________________ how much substance ionizes how much solute is present

  47. Example • 1 M HCl • 12 M HCl • 1 M H2CO3 • 12 M H2CO3 Strong and dilute Strong and concentrated weak and dilute weak and concentrated

  48. Ion Product Constant for Water (Kw) • Defn: equilibrium value for self ionization of water (H2O  H+ + OH-) • Formula Kw = [H+][OH-] = 1 x 10-14 ALWAYS ALWAYS ALWAYS

  49. Ion Product Constant for Water (Kw) • in pure water  [H+] = [OH-] = 1 x 10-7 M • in non pure water  (acidic/basic conditions), value of [H+] and [OH-] differ Remember pure water is neutral But still [H+][OH-] = 1 x 10-14

  50. Is solution acidic, basic, or neutral? • Acidic • Basic • neutral [H+] > [OH-] [H+] < [OH-] [H+] = [OH-]

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