Week of 12/1/14 Its 12/1/14, good morning! Distinguish between acids and bases and use indicators (including litmus paper, pH paper, and phenolphthalein) to determine their relative pH objective: discuss the pH scale and acids, the tests, properties and examples. Agenda for today 1. Bell \ringer: What do you think some acids are in your everyday life? 2. pretest 3.Competition for celebration 4.Study guide 5.Ppt on pH scale and acids Pretest for acids and bases Name Date period Its a party celebration Academics first everyone passes each assessment. I can only help with the top class but others can earn a celebration. When do we start? Today How do we earn ornaments for our tree? 1. Academics first: A. Hw ornament B. 100% hw 5 ornaments C. 100% passing assessments 5 ornaments 2.Responsibilities next: a. clean up room b. No blurt outs5 ornaments/reduced b.o. 1-4 ornaments c. 100% textbooks d. 100% with materials out when I come in from hallway. 3.Then courtesy: a. Helping other b. Maam, sir, please, thank you c. Good note from principal or sub How do we lose ornaments? 1.blurting out 2.No books 3.No materials 4.Not paying attention 5.Leaving trash 6.Inappropriate behavior 7.Talking in hallway. Its 12/3/14, good morning! Distinguish between acids and bases and use indicators (including litmus paper, pH paper, and phenolphthalein) to determine their relative pH objective: discuss the pH scale and acids, the tests, properties and examples. Agenda for today 1. Bell ringer: classify the substances below: is it an acid? A.grease B.Lemon juice C.Water D.Milk 1. Study guide check 2.Competition for celebration 3.Ppt on pH scale and acids 12/3/14 agenda Bell ringer Foldable: 4 pages folded like a book Title: acids and bases Heading: your name, date, and period Its 12/4/14, good morning! Distinguish between acids and bases and use indicators (including litmus paper, pH paper, and phenolphthalein) to determine their relative pH objective: discuss the pH scale and acids, the tests, properties and examples. Agenda for today 1. Bell ringer: which of the following are bases? (yes or no) A.Lemon juice B.detergent C.Sugar D.milk E.H 2 O F.H 2 SO 4 1.Homework check (except for 5 th and 7 th pds) 2.Competition for celebration show books, paper, pencil 3.Ppt on pH scale and acids Acid, base? Indicator? Pg 1 1.Substances can be classified as acids, bases, or neutral based on their pH. 2.Acids and bases are solutions usually with water as the solvent. 3.Indicators are substances that can be used to determine whether a solution is acidic, basic, or neutral. Reminder: Ornaments for your class? If you are not helping by bringing your book, hw, and materials to class, then you will not participate in the celebration. Classification of Substances p. 2 A. pH 1.The pH scale is a way to measure how acidic or basic a solution is. 2.The pH range of a solution is between 0 and The pH of pure water is 7. Any solution with a pH of 7 is a neutral solution. It is not an acid or a base. 4.The pH of an acidic solution is less than 7; the lower the number, the more acidic the solution. 5.The pH of a basic solution is greater than 7; the higher the number, the more basic the solution. B. Acidp Acids can be identified by their sour taste (for example lemons and oranges contain acids); 2.by their reaction with some metals such as zinc, and 3.by their reaction with bases to form a neutral pH solution (for example, vinegar reacting with limestone). C. Base 1.Bases can be identified by their bitter taste (for example, unsweetened cocoa has a bitter taste); 2.by its slippery feel (for example, dish detergent); and 3. by its reaction with acids to form a neutral pH solution (for example, an antacid to soothe an acid stomach). D. Neutral Solution 1.It is neither an acid nor a base. 2.For example, pure water is a neutral solution and has a pH of 7. pH Indicators p. 4 A. Litmus paper 1.Has a special dye on it that changes colors in the presence of an acid or base. 2.Blue litmus paper turns red in an acid, and stays blue in a base. 3.Red litmus paper turns blue in a base, and stays red in an acid. 4.Both red and blue litmus paper turn violet in a solution that is neutral (neither an acid nor a base). B. Phenolphthalein 1.Is used to test for the presence of a base. 2.It is a colorless chemical that turns magenta (bright pink) in a base, and stays colorless in neutral or acidic solutions. 3. Students need to know the indicator colors (magenta for base or colorless for acids or neutrals) for phenolphthalein. C. pH paper 1.Has a range of colors depending on the pH of the solution. 2.The color of the paper is compared to the chart of the vial to determine the pH. Divide p. 5 into 6 blocks like below. What is an acid?What is a base? Uses of acidsUses of bases Properties of acidsProperties of bases What is an acid? An acid is a solution that has an excess of H. It comes from the Latin word acidus that means "sharp" or "sour". The more H available, the more acidic the solution. Uses of Acids Acetic Acid = Vinegar Citric Acid = lemons, limes, & oranges. It is in many sour candies such as lemonhead & sour patch. Ascorbic acid = Vitamin C which your body needs to function. Sulfuric acid is used in the production of fertilizers, steel, paints, and plastics. Car batteries Properties of an Acid Tastes Sour Conduct Electricity Corrosive, which means they break down certain substances. Many acids can corrode fabric, skin,and paper Some acids react strongly with metals Turns blue litmus paper red Picture from BBC Revision Bitesases_1.shtmlases_1.shtml Explanation: Starting in 1983, instead of the solid copper, American pennies are made of zinc coated with a think layer of copper. Explanation: Starting in 1983, instead of the solid copper, American pennies are made of zinc coated with a think layer of copper. The zinc metal inside reacts with dilute sulfuric acid to form zinc sulfate and hydrogen (bubbles). The zinc metal inside reacts with dilute sulfuric acid to form zinc sulfate and hydrogen (bubbles). Copper does not react with dilute acids. After the zinc is dissolved (reacted), only the copper shell of the penny is left. Copper does not react with dilute acids. After the zinc is dissolved (reacted), only the copper shell of the penny is left. What is a base? A base is a solution that has an excess of OH- ions. Another word for base is alkali. Bases are substances that can accept hydrogen ions Properties of a Base Feel Slippery Taste Bitter Corrosive Can conduct electricity. (Think alkaline batteries.) Do not react with metals. Turns red litmus paper blue. Uses of Bases Bases give soaps, ammonia, and many other cleaning products some of their useful properties. The OH- ions interact strongly with certain substances, such as dirt and grease. Chalk and oven cleaner are examples of familiar products that contain bases. Your blood is a basic solution. Acid Base Reactions p. 6 A reaction between an acid and a base is called neutralization. An acid-base mixture is not as acidic or basic as the individual starting solutions. Acid Base reactions Each salt listed in this table can be formed by the reaction between an acid and a base. How can we use pH levels to test the health of a lake, river, or stream? Name Acid Color pH Range of Color Change Base Color Methyl violetYellow Blue Thymol blueRed Yellow Methyl orangeRed Yellow Bromocresol greenYellow Blue Methyl redRed Yellow ***LitmusRed Blue Bromothymol blueYellow Blue Thymol blueYellow Blue ***PhenolphthaleinColorless Pink ThymolphthaleinColorless Blue Alizarin yellow RYellow Red Indicators--just write the ***ones pH Scale A change of 1 pH unit represents a tenfold change in the acidity of the solution. For example, if one solution has a pH of 1 and a second solution has a pH of 2, the first solution is not twice as acidic as the second it is ten times more acidic.