Bellwork 1.26. 14

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Bellwork 1.26. 14

• Please walk in SILENTLY. Stop by the pick up
  table. Get started.
• 1.)Come up with 2-3 things you know about Acids
  and Bases
• 2.) Can you come up with some examples of an
  acid? Base?
• 3.) Where have you seen it in real life?
• 4.) When would they be useful to us? When might
  they be harmful to us?

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Agenda

• Bellwork
• Objective SWBAT differentiate the properties of
  an acid and base.
• Key Points
• Brain Pop
• Reading Notes
• Independent practice.

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Why is this important in LIFE?

• Questions that can be answered by learning about
  acids and bases.
• Why do you get more cavities from drinking soda?
• Buffers
• Important in your body
• How do you know your swimming pool safe to swim
  in?

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Acids

• Definition any compound that increases the
  number of Hydronium ions.
• Produce H (as H3O) ions in water (the
  hydronium ion is a hydrogen ion attached to a
  water molecule)
• Taste sour
• Corrode metals
• React with metals to give off hydrogen gas
• Conduct Electricity

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Ahhhhh
Although most acids are harmless, some are
harmful! For example, some acids eat through
plastic, clothing, skin and even corrode metal.
Sometimes these properties of strong acids are
useful. For example, hydrochloric acid in your
stomach helps digest food.
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Examples of Common Acids

• Sulfuric Acid - Car Battery
• Hydrochloric Acid - Stomach Acid
• Phosphoric Acid - Cold Drinks
• Lactic Acid - Milk
• Citric Acid - Oranges and Lemons
• Acetic Acid - Vinegar

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Bases
PROPERTIES of

• Definition any compound that increases the
  number of hydroxide ions
• Properties of bases
• Produce OH- (hydroxide) ions in water
• Soapy/slippery feel
• Bitter, chalky taste
• Conducts Electricity

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Some Examples of Bases

• Ammonia - Household cleaners
• Sodium Hydroxide - Drano
• Sodium Bicarbonate - Baking Soda
• KOH potassium hydroxide liquid soap
• Mg(OH)2- magnesium hydroxide-MOM Milk of
  magnesia
• Al(OH)3 -aluminum hydroxide- Maalox (antacid)

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BrainPop-Acids and Bases
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Acid or Base?
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Acid or Base?
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Reading Notes

• Please read the reading notes at your tables.
• Work together to answer the questions using your
  key points and your reading notes together.
• Move on to INDEPENDENT PRACTICE.

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Bellwork 1. 28.14
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Agenda

• Bellwork
• Objective SWBAT use the pH scale to identify a
  substance as an acid or base.

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pH Scale

• The pH scale is used to express the strength of
  acids and bases solutions. It ranges from 1-14.
• Acids have a pH less than 7
• Bases have a pH more than 7
• Nuetral solutions have a pH of exactly 7

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pH of Common Substances
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Check for Understanding

• Choose acid or base for the following
• 1. pH12
• 2. bitter taste
• 3. slippery
• 4. pH2

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Well, what is pH?

• pH is a measure of how many hydronium (H30) and
  hydroxide (OH-) ions are in a solution
• Remember, an acid produces hydronium (H30) ions
  when it dissolves in water
• A base produces hydroxide ions (OH-) when
  dissolved in water

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Weak vs. Strong

• The stronger a base is, the higher the pH
• The stronger an acid is, the lower the pH
• As we move closer to 7 from either direction,
  acids and bases become weaker and more neutral

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What does that mean?

• An acid is STRONGER if it is a LOWER pH
• pH1 is stronger than pH3
• A base is STRONGER if it has a HIGHER pH
• pH12 is stronger than pH10

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Practice

• Which is a stronger acid?
• A) pH4
• B) pH5
• Which is a weaker base?
• A) pH10
• B) pH14
• Which is a stronger base?
• A) pH12
• B) pH13

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HmmmAcid inside of me?

• The human stomach produces hydrochloric acid
  (HCl), commonly known as "stomach acid
• Stomach acid is made when you eat something, but
  when a person eats something requiring the
  stomach to work EXTRA hardsay, a pizzathe
  stomach may generate EXCESS hydrochloric acid,
  and the result is HEARTBURN

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Inside your insidesthe human stomach

• When this happens, people often take antacids,
  which contain chemicals such as
• aluminum hydroxide (AlOH3)
• or
• magnesium hydroxide (MgOH2)

What do these chemicals have in common?
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• THEY ARE BASES!!!!!! DUH Ms. Kim !
• Truetaking an antacid when there is excess acid
  in your stomach neutralizes the acid.

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Chemical Formulas of Acids and Bases

• The chemical formulas of acids generally start
  with H (or hydrogen)
• Ex HCl is hydrochloric acid, an acid found in
  the human stomach
• H2SO4-sulfuric acid, an acid found in car
  batteries
• Many bases have chemical formulas that end in OH

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Acid and Bases
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Acid and Bases
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Interesting fact

• Water is amphoteric (can act as an acid or a
  base!!!)