Titration Notes, part I

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Titration Notes, part I

• Neutralization Reactions

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Neutralization

• A reaction in which an acid and a base in aqueous
  solution produces a salt and water.

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What is a salt?

• An ionic compound made from the cation of a base
  and the anion of an acid.

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Neutralization Reactions

• NaOH HCl a
• KOH H2SO4 a
• Lithium hydroxide neutralizes nitric acid
• Phosphoric acid neutralizes calcium hydroxide

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Titration Reactions

• You can use a neutralization reaction to
  determine the concentration of an acid (or base)
  solution

using stoichiometry!!!
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Indicators

• In order to do so, you need an indicatora dye
  that changes colors at different pH
• In most titrations, phenolphthalein is used,
  because it turns from colorless to bright pink as
  a solution goes from acidic to basic.

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How Do You Titrate?

• 1) A measured amount of acid solution of unknown
  concentration is added to a flask.
• 2) Indicator is added to the acid.
• 3) Measured volumes of a base of known
  concentration are added until the indicator
  barely changes color.

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Titration Terms

• A buret is the device that we use for measuring
  volumes in a titration.

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Titration Terms

• The standard solution is the solution of known
  concentration added in step 3.

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Titration Terms

• The endpoint is the point at which the indicator
  changes color.

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The Mathematics of Titration

• Dont forget, the big M that stands for molarity
  is the same thing as moles/Liter!

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Practice Problem 1

• A 25mL solution of H2SO4 is neutralized by 18mL
  of 1.1M NaOH. What is the molarity of the H2SO4?

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Practice Problem 2

• A 19.0mL solution of H3PO4 is neutralized by
  22.7mL of 2.3M Ca(OH)2. What is the molarity of
  the H3PO4?

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Practice Problem 3

• How much 1.3M HCl is needed to neutralize 39.6mL
  of 2.1M NaOH?

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Practice Problem 4

• How much 2.9M NaOH would be needed to neutralize
  42.7mL of 3.1M H2SO4?