Acids

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Acids Bases

• Acid compound that produces hydrogen ions,
  H, when dissolved in water.
• Example
• HCl (g) H2O ? H (aq) Cl- (aq) H2O

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Acids Bases

• Base compound that produces hydroxide ions,
  OH-, when dissolved in water.
• Example
• NaOH (s) H2O ? Na (aq) OH- (aq) H2O

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Acid Properties

• Sour taste (never taste acids in lab)
• Vinegar (acetic acid)
• Lemon Juice (citric acid)
• Aspirin (acetosallicylic acid)
• Conductivity
• Acids are electrolytes
• Strong Acids Strong Electrolytes
• Weak Acids Weak Electrolytes

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Acid Properties

• Acids react with active metals to produce
  hydrogen gas.
• Zn(s) 2 HCl(aq) ? ZnCl2(aq) H2(g)

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Base Properties

• Bitter taste (never taste bases in lab)
• Mustard
• Cough Syrup
• Conductivity
• Bases are electrolytes
• Strong Bases Strong Electrolytes
• Weak Base Weak Electrolytes
• Bases feel slippery, sometimes soapy.

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Acid Strength

• Strong acids completely break apart into its
  ions are completely ionized in aqueous
  solutions.
• The equilibrium position lies very near the
  products (the ions)
• Strong acids (HCl, H2SO4, HNO3, H3PO4).
• HCl (g) H2O (l) ? H3O (aq) Cl- (aq)
• For strong acids, Keq is a big number.

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Acid Strength

• Weak acids do not completely break apart into
  its ions ionize only slightly in aqueous
  solution.
• The equilibrium position lies closer to the acid
  itself (reactant).
• CH3COOH (aq) H2O (l) ? H3O (aq)
  CH3COO- (aq)
• For weak acids, Keq is a small number.

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Base Strength

• Similar discussion can be applied to strong bases
  and weak bases.
• This is closely related to Keq.

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Acid Dissociation Constants

• http//solomon.bond.okstate.edu/thinkchem97/dissoc
  iation.htm

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Buret practice

• Your job is to come up with a safe procedures for
  the following.
• Filling the buret
• Accurately dispensing 15mL, 20mL, and 5mL water
  without refilling the buret.
• Cleaning the buret when finished.