Acids-and-bases-ppt.ppt
- 1. Acids & Bases They are everywhere.. In your food In your house EVEN IN YOU!!!!!
- 2. Objectives At the end of the lesson student are expected to: ď‚· Define acid and base; ď‚· Determine the different properties of acid and base; ď‚· Familiarize to the uses of acid and base.
- 3. What is an acid?  An acid is a solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp" or "sour".  The more H + ions, the more acidic the solution.
- 4. 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 Bites http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/acids_b ases_1.shtml
- 5. 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
- 6. 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
- 7. 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.
- 8. 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.
- 9. 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.
- 10. 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.
- 11. 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.
- 12. Acid – Base reactions  Each salt listed in this table can be formed by the reaction between an acid and a base.
- 13. Activity 1: Complete the table below by identifying whether a substance is acidic, basic or neutral given their pH value. SUBSTANCES/MIXTURES pH ACIDIC/BASIC/NEUTRAL 1. milk 6.3- 6.5 2. lemon juice 2.1 3. pure water 7.0 4. blood 7.4 5. detergent 11