ACIDS AND BASES! Learning Objective: To understand the difference between acids and bases and how to test if a solution is an acid or base. Do Now: Answer these questions in your labbook. Why does lemonade taste sour? Why does soap feel slippery? What makes cakes rise? Homework: Fill out Frayer models for acids and bases Agenda: 1.Reading 2.IBE 3.Active Notes Pg #TitleStandard Acids and Bases5e

What are we learning today? 5. e.Students know how to determine whether a solution is acidic, basic, or neutral.

IBE On your IBE sheet… – Fill in the Pre Lab section – Make your Hypotheses by filling out the prediction column in the table Use the droppers to put some liquid in each well, use the pH paper to test if it is an acid or a base.

What are Acids and Bases? Acid – any compound that increases the number of hydronium (H 3 O + ) when dissolved in water Base – Any compound that increases the number of hydroxide (OH) when dissolved in water

What are their properties? Acids – Taste: Sour – Conduct electricity: YES – Corrosive: YES OTHER: Destroys body parts (skin) and clothing – Other: Reacts with metals Bases – Taste: Bitter – Corrosive: YES – Conduct electricity: YES – Other: Slippery feel

What are some Examples? Acids – Lemons – Vinegar – Grapes – Sodas – Car batteries – Your stomach’s digestive “juices” called gastric acid Bases – Baking bowder – Chalk – Soap – Saliva in your mouth

How do we use acids? Acids – Sulfuric acid Make paint, and detergent In car batteries – Nitric acid In fertilizer – Hydrochloric acid Digestion in your stomach – Citric acid In oranges

How do we use bases? Bases – Sodium hydroxide Make soap and paper – Amonina Cleaners and fertilizers – Antacids Treat heartburn

Connection to the IBE

What is pH? Scientific Definition Our Definition How many hydronium ions (H 3 O + ) are in a solution How acidic is the solution. Meaning, is a solution acidic, is it basic, or is it neutral?

What is the pH scale? Acidic Basic Neutral DIRECTIONS: Label your pH Scale as seen above Acidic: -5 to 6 Neutral: 7 Basic: 8-14 You MAY color it in with colored pencils, remember to shade dark to light IF those colors are in your pencil case. If not, maybe you shouldn’t have RUINED the materials I bought for the class. Disrespect. 

pH Scale Activity Sort - Materials Each student should have 1 colored pH scale to glue into your notebook. Each pair should have one cardstock pH scale, and 1 bag.

pH Scale Activity Sort – Set Up 1.Take the tabs out of the bag, and spread them out face up. 2.Count your strips to make sure you have 15. REMINDER: Acid are pH less than 7 Bases are pH greater than 7

pH Scale Activity Sort – The Game 1.I will read the clues one at a time. 2.You and your pair should be placing the tabs into the correct spots on the pH scale 3.At the end we will see how many you got right

Clue #1 1) We drink acids when we are thirsty.

Clue #2 2) Water is pH neutral.

Clue #3 3) This is found in Utah and it has a concentration of 1/1,000th for Hydrogen Ions.

Clue #4 4) The strongest acid is found in car batteries.

Clue #5 5) The strongest base unclogs your sink.

Clue #6 6) You may swim in this very weak base during vacation.

Clue #7 7) This second strongest acid is found in your stomach.

Clue #8 8) You may spit out this very weak acid.

Clue #9 9) Your favorite soft drink has 10,000 times more Hydrogen Ions than pure water.

Clue #10 10) Ammonia has a concentration of 1/10,000th for Hydrogen Ions.

Clue #11 11) Bleach is the second strongest base.

Clue #12 12) Lemon juice is more acidic than soft drinks.

Clue #13 13) Coffee is less acidic than tomato juice.

Clue #14 14) Baking soda is more basic than sea water.

Clue #15 15) In your bathtub, it may have this pH as it goes down the drain.

Take out the pH scale glued into your notebook. Open your notebook and copy down the examples of each pH range into your notebook.

HOMEWORK Complete the Vocabulary Foursquare for Acids and bases. I will collect this tomorrow.

What is an Indicator? You may be wondering – How do we know if a solution is an acid or a base? – An indicator changes color in the presence of an acid or base

Indicator examples pH paper litmus paper indicator solutions (ex. Bromophenol Blue) pH meters Cabbage juice

AcidBase What happens to bromophenol blue in the presence of each of acids and bases? What happens to litmus paper in the presence of each of acids and bases? Yellow Darker Blue Red Blue

Indicator LAB! Elect one person on you team to be the gatherer. Elect one person on your team to be your cleaner. These are the only students allowed out of their seats at one time.

Exit Slip 1.Why does lemonade taste sour? 2.If a substance has a high number on the pH scale then it is a ________________? 1.How do we find out if a substance is an acid or base?

Exit Slip - Answers 1.Why does lemonade taste sour? 2.If a substance has a high number on the pH scale then it is a ________________? 1.How do we find out if a substance is an acid or base? Because it is acidic, and acids taste sour Base, bases have a pH > 7 We use an indicator, such as pH paper, litmus paper, or cabbage juice