Do Now: Review What are some uses for acids and bases? What are some uses for acids and bases? What substances are acidic? What substances are acidic? What substances are basic? What substances are basic? What characteristics do acids have? What characteristics do acids have?

Title 46: Title of Lesson Date: Summary of Introduction: Challenge: Key Words: acid, base, neutral Procedure: I understand, sign Materials: Data: Analysis: 1,3, 4 Notes to myself for tomorrow:

Title 48: Title of Lesson Date: Summary of Introduction: Challenge: Key Words: acid, base, neutralization Procedure: I understand, sign Materials: Data: Analysis: 1,2,3, 4 Notes to myself for tomorrow:

1.What happened to hydrochloric acid when you diluted it with water ? a.Remained Constant b.Became more acidic c. Became very basic d. Became less acidic/more neutral Exit Ticket 1

Acids Often taste sour Often taste sour Strong acids can burn skin & eyes Strong acids can burn skin & eyes Strong acids can dissolve metals Strong acids can dissolve metals Examples: Examples: Lemon juice Lemon juice Vinegar Vinegar Car battery acid Car battery acid (dangerous!)

Bases Can taste bitter, sweetish, or salty Can taste bitter, sweetish, or salty Strong bases can burn skin & eyes Strong bases can burn skin & eyes Bases react more easily with protein than with metal; they are often used for cleaning Bases react more easily with protein than with metal; they are often used for cleaning Examples: Examples: Milk Milk Baking soda Baking soda Soap Soap Drain cleaner Drain cleaner (dangerous!)

Some substances are not really an acid or a base: For example, pure water Some substances are not really an acid or a base: For example, pure water

Most Substances: Can be identified as either acidic or basic Can be identified as either acidic or basic Like the soil in our backyard. Like the soil in our backyard.

pH A special name is given to the acid or base characteristic that a substance has: A special name is given to the acid or base characteristic that a substance has: It is called: pH It is called: pH “p” stands for potential and “H” stands for hydrogen; hence, the potential of a substance to attract hydrogen ions “p” stands for potential and “H” stands for hydrogen; hence, the potential of a substance to attract hydrogen ions

How Does It Work? The paper is treated with chemicals that change color to show the pH. The paper is treated with chemicals that change color to show the pH. When the paper touches the substance being tested, it turns a specific color to tell if the substance is an acid or a base. When the paper touches the substance being tested, it turns a specific color to tell if the substance is an acid or a base.

The pH Scale pH scale ranges from pH scale ranges from pH 7 is neutral; neither acid nor base pH 7 is neutral; neither acid nor base Pure water is pH 7 Pure water is pH 7 Low pH (0-6.9) = acid Low pH (0-6.9) = acid High pH (7.1-14) = base High pH (7.1-14) = base The closer to the ends of the scale, the stronger the solution is The closer to the ends of the scale, the stronger the solution is

Acid Any substance which has a pH of value of less than 7 is considered an acid Any substance which has a pH of value of less than 7 is considered an acid Acid Neutral Base Acid Neutral Base

Base Any substance which has pH value greater than 7 is a base Any substance which has pH value greater than 7 is a base Acid Neutral Base Acid Neutral Base

pH 7 A pH of 7 is called neutral—neither acid nor base. A pH of 7 is called neutral—neither acid nor base Acid Neutral Base Acid Neutral Base

Acidic or Basic If the number is less than 7 the substance or water is acidic If the number is less than 7 the substance or water is acidic If the number is more than 7 the substance or water is basic If the number is more than 7 the substance or water is basic

The pH Scale

Why is pH important? Soil has to be in a certain pH range for plants to grow and stay healthy. Fish can’t live if the pH is too high or too low