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?

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

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?

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

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. Most acids are harmless, but some can be harmful! Some can eat through through plastics, clothing, metals, or even skinSo, don’t touch acids you are unfamiliar with These properties can be helpful though. For example, hydrochloric acid in your stomach helps digest food.

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

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

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)

BrainPop-Acids and Bases

Acid or Base?

Acid or Base?

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.

Bellwork 1. 28.14

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

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

pH of Common Substances

Check for Understanding Choose acid or base for the following: 1. pH=12 2. bitter taste 3. slippery 4. pH=2

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

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

What does that mean? An acid is STRONGER if it is a LOWER pH pH=1 is stronger than pH=3 A base is STRONGER if it has a HIGHER pH pH=12 is stronger than pH=10

Practice Which is a stronger acid? Which is a weaker base? A) pH=4 B) pH=5 Which is a weaker base? A) pH=10 B) pH=14 Which is a stronger base? A) pH=12 B) pH=13

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

Acid and Bases

Acid and Bases

Water is amphoteric (can act as an acid or a base!!!) Interesting fact… Water is amphoteric (can act as an acid or a base!!!)