Neutralization

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Neutralization

• Section 19.4

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Neutralization

• Rxn. b/t acids bases
• Produces a salt water
• Mg(OH)2 2HCl ? MgCl2 2H2O
• Titration method for determining soln. of
  known volume with a soln. of known concentration
• Equivalence point point at which moles H
  OH- can happen at any pH
• Acid-base indicator chemical dye whose color
  changes in acidic/basic soln.
• End point point at which the indicator changes
  color

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Titration Problems

• Write balanced equation.
• Convert mL of known soln. to L
• Using molarity, find moles of known
• Mol known to mol unknown (stoichiometry)
• Determine molarity of unknown

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Practice

• What is the molarity of a CsOH solution if 30.0
  mL of the solution is neutralized by 26.4 mL of
  0.250M HBr solution?
• What is the molarity of a nitric acid solution if
  43.33 mL of 0.100M KOH solution is needed to
  neutralize 20.00 mL of unknown solution?
• What is the concentration of a household ammonia
  cleaning solution if 49.90 mL of 0.5900M HCl is
  required to neutralize 25.00 mL solution?

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Buffers

• Buffered soln. resist changes in pH when
  limited amounts of acids/bases added
• How does it work?
• Contain mixture of acid conj. Base or vise
  versa
• These ions react with added H or OH- resisting
  pH change.
• Buffer capacity amt. acid/base that the buffer
  can withstand
• Used to maintain body pH (variations gt 0.3 pH can
  be fatal)