Acids and Bases.

Presentation on theme: "Acids and Bases."— Presentation transcript:

1 Acids and Bases

2 Acid and Bases

3 Acid and Bases

4 Acid and Bases

5 Acids Acids donate hydrogen protons to water when they dissolve. Creating H+ Water becomes hydronium ions (H3O+) Acids that ionize completely are strong acids.

6 Properties of acids Sour taste Produce hydronium ions in solutions
React with metals Corrosive Conduct electric current Change colors of indicators Turns blue litmus paper red Has a pH less than 7

7 Strong acids The six strong acids are: Hydrochloric acid HCl
Hydrobromic acid HBr Hydroiodic acid HI Perchloric acid HClO4 Nitric acid HNO3 Sulfuric acid H2SO4 All other acids are weak acids. Strong acids completely ionize in water giving up their hydrogen 100%

8 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

9 Bases (alkali) When bases are dissolved in water they produce hydroxide ions (OH-) Bases are substances that can accept hydrogen ions Bases can be just as reactive as acids and are just as dangerous if not handled properly

10 Properties of bases Slippery or filmy Taste bitter
Conduct electric current Changes red litmus paper blue Do not react with metals. Has pH higher than 7

11 Strong bases Potassium hydroxide KOH Barium hydroxide Ba(OH)2
Caesium hydroxide CsOH Sodium hydroxide NaOH Strontium hydroxide Sr(OH)2 Calcium hydroxide Ca(OH)2 Lithium hydroxide LiOH Rubidium hydroxide RbOH Strong bases ionize completely in water. All other bases are weak bases

12 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.

13 The pH scale The strength of an acid or base is measured on the pH scale pH is a measure of the concentration of hydronium ions found in a solution The range of the scale is 0-14 but 7 is considered neutral

14 Acids have a pH less than 7
Base have a pH greater than 7 Pure water has a pH equal to 7

15 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.

16 Common household items and pH

17 Indicators Indicators are special compounds that change colors when exposed to and acid or base Some, like litmus paper, just turn to one color and can only tell you if its an acid or base but not the strength

18 Blue litmus paper turning Red litmus paper turning red This is an acidic blue this is an alkaline
solution (base) solution

19 Indicators Litmus paper has its limits. it cannot tell you how strong the acid or base is. Special chemicals can change certain colors to indicate strength of acids and bases

20 These paper strips have been soaked in the chemicals on the left so they can be dipped in solutions to test These chemical solutions have color values to indicate pH level

21 Acid base neutralization
Acids and bases react in a special chemical reaction called _______________ This name means that the pH of the solution will move closer to 7 after the reaction occurs ___________ and _________ are always products of these reactions Ex HCl + NaOH -- NaCl + H2O