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Acids & Bases They are everywhere.. In your food In your house EVEN IN YOU!!!!! https://www.youtube.com/watch?v=mnbS56HQbaU https://www.youtube.com/watch?v=i2x4foEuRcI Intro Video up to 1:10 OBJECTIVES What is an Acid? Properties of an Acid Strong Acid Weak Acid Uses of Acid What is a Base Difference between Bases and Alkali Alkali Properties of Alkali Properties of Bases Uses of Bases What is an Indicator? Where do we find Acids and Bases? They are compounds... that are fundamental to the functioning of our world. – we need them! They are essential to Life; They are responsible for many, many processes in nature; They are important in many products and processes we have come to expect in our daily lives. Continue Video to 3:15 What is an acid? An acid is a solution that has an excess of Hydrogen (H+ ions). The more H+ ions, the more acidic the solution. Properties of an Acid Tastes Sour Conducts Electricity Corrosive; (they break down certain substances. Many acids can corrode fabric, skin,and paper). Some acids react strongly with metals. Turns blue litmus paper red Chemical Properties of Acid Acids react with bases to form a salt and water only Ex. Sulphuric acid reacts with copper (II) oxide to form a salt called copper (II) sulphate and water. This reaction is called neutralisation. A Strong Acid A Weak Acid Some Common Acids Uses of Acids Acetic Acid = Vinegar Citric Acid = lemons, limes, & oranges. It is in many sour candies such as lemonhead & sour patch. Hydrochloric acid is used in industry to remove rust from metal before they are painte. Ascorbic acid = Vitamin C which your body needs to function. Sulfuric acid is used in the production of fertilizers, steel, paints, and plastics. Also in Car batteries. Checkpoint What ions do acids produce in water? State three properties of acids Explain what is meant by a strong acid. Give one example. Explain what is meant by a weak acid. Give one example. Some dry citric acid crystals are placed on a dry piece of litmus paper. Will there be a colour change? Explain your answer 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 H + OH = ________ Bases Alkalis Difference between Bases and Alkali Chemical Properties of Alkali Chemical Properties of Alkali 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 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. Video to 12:37 pH scale Uses of Bases Sodium hydroxide and potassium hydroxide are used in soap making Ammonia solution is used in window cleaners Magnesium hydroxide is used I toothpastes to neutralise the acid produced by bacteria Calcium hydroxide (slaked lime) is used to neutralise acids found in acidic soil Some Common Alkali Checkpoint What is a base? Give 3 examples. Define what is an alkali. Give 3 examples State three properties of alkalis Explain why iron (II)hydroxide is a base, but not an alkali. Write a balance chemical equation for the following reactions: A. potassium hydroxide + ammonium chloride B. Calcium hydroxide + ammonium chloride Indicators Video to 12:37 Indicators pH Scale pH is a measure of how acidic or basic a solution is. • The pH scale ranges from 0 to 14. Acidic solutions have pH values below 7 A solution with a pH of 0 is very acidic. A solution with a pH of 7 is neutral. • Pure water has a pH of 7. • Basic solutions have pH values above 7. pH Scale • A change of 1 pH unit represents a tenfold change in the acidity of the solution. (X 10) • 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. Universal Indicator Types of Oxides Types of Oxides Acid – Base Reactions 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. Checkpoint Name three common indicators and their colour change in strong acidic and strong alkaline solutions. What is mean by the pH of a solution? What are the four types of oxides? Give an example of each What colours would you expect to see when the follwoign indicators are added to a solution of pH 5?: a. litmus b. phenolphthalein c. methyl orange Salts Examples of Salts Uses of Salts Soluble and Insoluble Salts Acids and Bases in Nature @ 15:20 Acids and Bases are constantly at work interacting with each other; otherwise all our water would be acidic….No? Explain… After viewing the final episode, answer these Qs: 1. How does pH affect plant growth and gardeners gardens? 2. How does pH affect farmers’ crops? 3. What is the cause of acid rain? 4. How does acid rain affect living and nonliving things?