Acid and Base Chemistry

1
Acid and Base Chemistry

• Chapter 23

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Acids Bases

• Sour taste (lemon) Bitter taste (almond)
• Low pH High pH
• Turns blue litmus red Turns red litmus blue
• React with metals ? H2 Feel slick (soapy)
• Electrolyte Electrolyte
• Corrosive/Caustic Corrosive/Caustic

3
Acids

• Arrhenius Release H ions into water to form the
  hydronium ion (H3O).
• Bronsted-Lowry Proton donors
• Lewis Electron pair acceptors

4
Bases

• Arrhenius Release OH- ions into water.
• Bronsted-Lowry Proton acceptors
• Lewis Electron pair donors

5
Examples

• Strong Acids HCl, H2SO4, HNO3
• Weak Acids HC2H3O2, HF
• Strong Bases LiOH, NaOH, KOH,
• Weak Bases Al(OH)3, NH3

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What Is a Strong Acid?

• Strong acids (or strong bases) dissociate 100
  when dissolved in water. This means the H (or
  OH-) breaks away from its molecule.

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Reactions

• Acid Metal ? H2 Salt
• Acid Carbonates
• ? H2O CO2 Salt

8
Salts

• Salt cation of base with anion of acid
• Examples KCl, Na2SO4 , NH4 NO3

9
Neutralization

• Acid Base ? Water Salt
• Examples
• HCl KOH ? H2O KCl

10
Titration

• A solution of known concentration is added to a
  measured amount of sample of unknown
  concentration until some endpoint is reached.
• Endpoints are usually marked by the color change
  of an indicator.

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Indicators

• Exhibit one color in basic solutions and a
  different color acidic solutions.
• Penolphthalein (colorless-pink)
• Litmus (red-blue)
• Bromothymol Blue (yellow-blue)
• Methyl Red (yellow-red)
• Red Cabbage Juice
• Certain Flowers

12
Buffers

• Buffer solutions undergo only slight pH changes
  when an acid or a base is added.
• Buffers contain a weak acid (HF) and its
  conjugate base (F-).