Acid, Base, or Neutral

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Acid, Base, or Neutral
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Today You Will

• Define acid and base
• Determine if a substance is acidic or basic
• Explore why we learn about acids and bases

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Why Learn about Acids Bases?

• What do you think is the pH level of NYC tap
  water?
• The pH of a swimming pool must be checked
  periodically. Why?
• Is it important for Lakes Rivers to maintain a
  certain pH?

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Arrhenius Acids and Bases

• Acids produce H in aqueous solutions
• water
• HCl H(aq) Cl- (aq)
• Bases produce OH- in aqueous solutions
• water
• NaOH Na(aq) OH- (aq)

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Acids

• Produce H (as H3O) ions in water
• Produce a negative ion (-) too
• Taste sour
• Corrode metals
• React with bases to form salts and water

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Bases

• Produce OH- ions in water
• Taste bitter, chalky
• Feel soapy, slippery
• React with acids to form salts and water

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Learning Check AB1

• Describe the solution in each of the following
  as 1) acid 2) base or 3)neutral.
• A. ___soda
• B. ___soap
• C. ___coffee
• D. ___ wine
• E. ___ water
• F. ___ grapefruit

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Solution AB1

• Describe each solution as
• 1) acid 2) base or 3) neutral.
• A. _1_ soda
• B. _2_ soap
• C. _1_ coffee
• D. _1_ wine
• E. _3_ water
• F. _1_ grapefruit

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Learning Check AB2

• Identify each as characteristic of an A) acid
  or B) base
• ____ 1. Sour taste
• ____ 2. Produces OH- in aqueous solutions
• ____ 3. Chalky taste
• ____ 4. Is an electrolyte
• ____ 5. Produces H in aqueous solutions

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pH

1. pH is a measure of how acidic or basic a solution
   is.
2. A pH of a solution depends on the concentration
   of hydrogen (H).
3. The pH scale ranges from 0 to 14.
4. Acids range from 0-7.
5. Bases range from 7-14.
6. 7 is neutral.

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Indicators

• An indicator is a compound (dye) that changes
  color in an acid or base or in both.

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Indicators
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pH of common household solutions

• Lemon juice -2.2
• Soda- 2.9-3.3
• Milk- 6.4
• Distilled water- 7
• Baking soda- 8.3
• Ammonia-11.0