ACIDS, BASES,

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ACIDS, BASES, THEIR SOLUTIONS
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The pH Scale

• Is a substance an acid or a base?

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ACIDS

• a compound that increases the number of hydrogen
  ions (H) when dissolved in water
• 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 ascorbic acid (Vitamin C) orange juice
• Carbonic 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. Its used in making metals,
  paper, paints, and fertilizers.

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BASES

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

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Uses of Bases

• used in soaps (remember, bases are slippery)
• 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

• You can detect an acid or a base using an
  indicator.
• INDICATOR - A substance that changes color in the
  presence of an acid or a base.

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INDICATORS

• Litmus paper is an indicator
• An acid turns blue litmus paper red
• A base turns red litmus paper blue
• Cabbage juice can be used as an indicator.
• pH paper- turns a color then match it to the pH
  scale given.
• pH meter- will give you a number for the solution.

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HOW DO WE MEASURE pH WHAT IS pH?
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pH stands for powers of Hydrogen.---Its a
measure of the hydronium ion concentration in a
solution.
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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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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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Lets see what youve learned!

• Mrs. Borras wants to know what youve learned.
  Answer the following questions carefully.
• DO NOT ANSWER OUT LOUD!!!!! Write it down.

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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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Question 6

• 409 cleaner contains ammonia that has a pH of 12.
  What will 409 do to red litmus paper?

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Question 7

• A soft drink has a pH of 3.2. What will it do to
  a piece of red litmus paper?

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Youve just completed Mrs. Borras Quiz

• Lets see how you did!