What comes to mind when someone says acid?

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Acids and Bases

• What comes to mind when someone says acid?

• What comes to mind when someone says base?

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The pH Scale

• Is a substance an acid or a base?

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ACIDS

• An acid is a compound that increases the number
  of hydrogen ions when dissolved in water (H).
• An acid solution tastes sour.
• An acid can change the color of certain
  compounds.

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What is an ion?

• An ion is an atom that has lost or gained an
  electron giving it a positive () or negative (-)
  charge.

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USES OF ACIDS

• Citric acid and ascorbic acid (Vitamin C) are
  found in orange juice.
• Carbonic acid and phosphoric acid give a bite
  to soft drinks.
• Acids in your stomach aid in digestion.
• Sulfuric acid is the most widely used industrial
  acid in the world. It is used in making metals,
  paper, paints, and fertilizers.

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BASES

• A base is any compound that increases the number
  of hydroxide ions (OH-) when mixed with water.
• A base solution tastes bitter.
• A base solution feels slippery.
• A base can change the color of certain compounds.

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Uses of Bases

• Bases are used in soaps. (remember, bases are
  slippery)
• Bases are used to make paper, in oven cleaners,
  and to unclog drains.
• Ammonia is a base and is used in many household
  cleaners.

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Detecting Acids and Bases

• We are going to use Vernier Probeware to detect
  acid and base concentrations.

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HOW DO WE MEASURE pH?
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NEUTRAL
ACID
BASE
0 1 2 3 4 5 6 7 8
9 10 11 12 13 14
The pH Scale
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It's important to control the pH of a plant to
ensure proper growth.

• The pH affects the availability of plant
  nutrients. A low pH can drain nutrients from the
  soil so they don't reach plant roots. Soil pH
  also controls the solubility (mixability) of
  nutrients and minerals that are needed for plants
  to grow. Solubility is important because fourteen
  of the seventeen plant nutrients that are
  necessary for plant growth are derived from soil
  solution.

• Although most plants thrive better in acidic
  soils, others prefer soils that are basic
  (alkaline). For optimum growing, most plants need
  a soil that has a pH range from 5.8 to 7.0.

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Lets see what youve learned!

• Professor Know-It-All wants to know what youve
  learned. Answer the following questions
  carefully.

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Question 1

• Lemon juice has a pH of 2.2. Is it an acid or a
  base?

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Question 2

• Detergents such as Tide have a pH of about 10. Is
  Tide an acid or a base?

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Question 3

• Seawater has a pH of 8.2. Is seawater an acid or
  a base?

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Question 4

• The inside of your mouth has a pH of 7. Is it an
  acid or a base?

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Question 5

• How do you think we came up with the term acid
  rain?

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Youve just completed Professor Know-It-Alls Quiz

• Lets see how you did!