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Introduction to Acids and Bases

Introduction to Acids and Bases. Chemistry. Bell work. Name the following compounds: NaCN PO 3 Li 2 SO 3 NH 3 Write the formulas of the following compounds: Ammonium sulfate Copper (II) hypochlorite. Agenda. Bell work Notes: Acids and bases Group practice: Naming acids

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Introduction to Acids and Bases

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  1. Introduction to Acids and Bases Chemistry

  2. Bell work • Name the following compounds: NaCN PO3 Li2SO3 NH3 • Write the formulas of the following compounds: Ammonium sulfate Copper (II) hypochlorite

  3. Agenda • Bell work • Notes: Acids and bases • Group practice: Naming acids • Wrap up: acids/bases • HW: Finish Naming Acids table

  4. Objectives • Identify 3 properties of acids and bases • Identify acids and bases based on pH value • Identify hydronium ion • Identify strong and weak acids and bases • Show strong and weak electrolytes in equations • Define electrolyte • Identify acids and bases based on chemical formulas • Name acids and bases

  5. Acids and Bases are All Around • Oranges! Citric Acid DUH • Fruit Juices, Soft Drinks, Warheads – all acidic (not necessarily acids) • Many cleaners are basic • From Car Batteries and Coke® to Mr. Clean rely on acids and bases

  6. Acids • Most foods are acidic • Sour, tart, or sharp taste • NEVER TASTE TEST IN LAB • Acidic pH Range: 0 – less than 7 • React with many metals (activity series) • Many acids are caustic (meaning corrosive or burning) • Formula always starts with _____________ • Hydrogen (example HCl)

  7. Acids are Electrolytes • Like Gatorade • Electrolyte: Conducts Electricity • Ions must be present to conduct electricity • Acids generate the hydronium ion (H3O+) when placed in water • HCl + H2O → H3O+ + Cl- • More [H3O+]= More Acidic (lower pH)

  8. Bases • Many cleaners are basic • Slippery feel • Attack oils on skin (a good cleaning property) • NEVER TOUCH TEST A BASE IN LAB • Hydrophillic – “water loving” • Sometimes will absorb water from the air to become a liquid • Generates hydroxide ions (OH-) • Basic pH = greater than 7 to 14

  9. Strong vs Weak • Strong Acids and Bases • Dissociate completely (look for →) • Strong: HCl + H2O → H3O+ + Cl- • Dissociates/Ionizes Completely • Weak do not dissociate completely • Instead, they form an equilibrium represented by double arrows facing both ways: ↔ • Weak: HClO3 + H2O ↔ H3O+ and ClO3- • Forms Equilibrium

  10. Equilibrium – What is it? • A balance between products and reactants • Products form, but also react and form a balance • Reaction never stops but balances out

  11. Strong or Weak? • NH3 + H2O ↔ NH4+ + OH- • Weak (double arrow) • HNO3 + H2O → H3O+ + NO3- • Strong (single arrow)

  12. Strong Acids: • HCl – Hydrochloric Acid • HI – Hydroiodic Acid • HBr – Hydrobromic Acid • H2SO4 – Sulfuric Acid • HNO3 – Nitric Acid • HClO4 – Perchloric Acid • HClO3 – Chloric Acid

  13. Strong Bases • Hydroxides of Alkali Metals • Hydroxides of Alkaline Earth Metals – except Beryllium and Magnesium

  14. A test: Acid or Base • What am I? • HClO3 Acid • HI Acid • NaOH Base • H2CO3 Acid • Mg(OH)2 Base

  15. Naming Acids and Bases • How can you identify an acid? • How can you identify a base? • Naming bases: • Naming acids: 2 categories of acids, different rules for naming each • Binary acids • Oxyacids

  16. Binary acids • H + one element • Start with hydro- • End with –ic and acid • Hydro______ic acid • Ex: HBrHCl H2Se

  17. Oxyacids • H + polyatomic ion • Start with name of polyatomic ion • If end of polyatomic ion name ends with –ate, change the ending to –ic • If the end of polyatomic ion name ends with –ite, change the ending to –ous • Ex: HNO3 HNO2 HBrO3

  18. Practice • Acid naming table

  19. Wrap Up • Identify 3 properties of acids and bases • Identify acids and bases based on pH value • Identify hydronium ion • Identify strong and weak acids and bases • Show strong and weak electrolytes in equations • Define electrolyte • Identify acids and bases based on chemical formulas • Name acids and bases

  20. Homework • Finish Acid Naming table • Endings of polyatomics tell you how many oxygens • Per _____ ate +1 O • ____ate base # Os • ___ite - 1 O • Hypo _____ ite - 2 O

  21. Homework • Naming Acids and Bases

  22. Bell work • Pull out acid naming practice. • Name the following compounds: HClO2 HF Fe(OH)2 MgCl2 • Write the formulas for the following compounds: Hydroiodic acid Titanium (III) hydroxide Oxygen difluoride Nitric acid

  23. Agenda • Bell work • Review last class’s material • 10 minutes to come to consensus on naming homework • What color is that? • Notes: Debrief of what color is that, acid/base theories, conjugate acids/bases • HW: Naming acids and bases with acid/base questionnaire

  24. Last class’s objectives • Identify 3 properties of acids and bases • Identify acids and bases based on pH value • Identify hydronium ion • Identify strong and weak acids and bases • Show strong and weak electrolytes in equations • Define electrolyte • Identify acids and bases based on chemical formulas • Name acids and bases

  25. Strong vs Weak • Strong Acids and Bases • Dissociate completely (look for →) • Strong: HCl + H2O → H3O+ + Cl- • Dissociates/Ionizes Completely • Weak do not dissociate completely • Instead, they form an equilibrium represented by double arrows facing both ways: ↔ • Weak: HClO3 + H2O ↔ H3O+ + ClO3- • Forms Equilibrium

  26. Equilibrium – What is it? • A balance between products and reactants • Products form, but also react and form a balance • Reaction never stops but balances out

  27. Strong or Weak? • NH3 + H2O ↔ NH4+ + OH- • Weak (double arrow) • HNO3 + H2O → H3O+ + NO3- • Strong (single arrow)

  28. Strong Acids: • HCl – Hydrochloric Acid • HI – Hydroiodic Acid • HBr – Hydrobromic Acid • H2SO4 – Sulfuric Acid • HNO3 – Nitric Acid • HClO4 – Perchloric Acid • HClO3 – Chloric Acid

  29. Strong Bases • Hydroxides of Alkali Metals • Hydroxides of Alkaline Earth Metals – except Beryllium and Magnesium

  30. A test: Acid or Base • What am I? • HClO3 Acid • HI Acid • NaOH Base • H2CO3 Acid • Mg(OH)2 Base

  31. Naming Acids and Bases • How can you identify an acid? • How can you identify a base? • Naming bases: • Naming acids: 2 categories of acids, different rules for naming each • Binary acids • Oxyacids (ternary acids)

  32. Binary acids • H + one element • Start with hydro- • End with –ic and acid • Hydro______ic acid • Ex: HBrHCl H2Se

  33. Oxyacids • H + polyatomic ion • Start with name of polyatomic ion • If end of polyatomic ion name ends with –ate, change the ending to –ic • If the end of polyatomic ion name ends with –ite, change the ending to –ous • Ex: HNO3 HNO2 HBrO3

  34. Polyatomic nomenclature • Endings of polyatomics tell you how many oxygens • Per _____ ate +1 O • ____ate base # Os • ___ite - 1 O • Hypo _____ ite - 2 O

  35. Acid naming practice • 10 minutes to come to consensus in groups

  36. Agenda • Bell work • Review last class’s material • 10 minutes to come to consensus on naming homework • What color is that? • Notes: Debrief of what color is that, acid/base theories, conjugate acids/bases • HW: Naming acids and bases with acid/base questionnaire

  37. Objectives • Name acids, bases, and salts • Investigate properties of various substances (what color is that?) • Explain acid/base theories as they relate to presence of H+ and OH- • Identify conjugate acid/base pairs • Homework: Naming acids and bases & acid/base questionnaire

  38. Bell work • Pull out Acid Naming Practice table • What are at least 4 categories into which we can group chemical compounds? • Use what you know about these categories to name the following: Na2O Cu(Cr2O7)2 PO3 HC6H5COO FeSO4 Ca3N2 NO2 H2S

  39. Agenda • Bell work • 10 minutes for consensus on Acid Naming Table • Notes: Acid/base theories, conjugate acids and bases • Debrief: What color is that? • HW: Naming Acids and Bases homework

  40. Objectives • Name acids and bases • Explain acid/base theories as they relate to presence of H+ and OH- • Define amphoteric • Predict products of acid/base interactions with water • Identify conjugate acid/base pairs

  41. The Chemists • Svante Arrhenius: 1890 • Acid: Any substance, that when added to water, causes hydronium ion concentration to increase • Base: Any substance, that when added to water, causes hydroxide ion concentration to increase • The problems: • Not all acids/bases can be aqueous (dissolve in water) • Some can function as both (WATER!) • These are called amphoteric

  42. The Chemists • Brønsted-Lowry • Two separate people – but the same definition • Acid: Any species that can donate a proton (an H+) • Base: Any species that can accept a proton • HNO3 + H2O → H3O+ + NO3- • What donated the proton? HNO3 (the acid) • What accepted the proton? H2O (the base)

  43. Conjugate Acids and Bases • NH3 + H2O ↔ NH4+ + OH- • What is the acid? H2O • What is the base?NH3 • NH4+ + OH-↔ NH3 + H2O • What is the acid? NH4+ • What is the base? OH- • These are called the conjugate acid and base – what would happen when the reaction reversed

  44. Conjugate acids and bases • Conjugate acid: has one more H+ than base • Conjugate base: has one fewer H+than acid

  45. Conjugate Acid and Base Practice • NH3 + H2O ↔ NH4+ + OH- • Acid • H2O • Base • NH3 • Conjugate Acid • NH4+ • Conjugate Base • OH-

  46. Conjugate Acid and Base Practice • HF + H2O → H3O+ + F- • Acid • HF • Base • H2O • Conjugate Acid • H3O+ • Conjugate Base • F-

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