1. Acids and Bases
Lesson 15

2. Acids
Acids are traditionally considered any chemical compound that, when dissolved in water, gives a pH of  less than 7.0. They also:
Taste sour
Are good conductors of electricity (they release H+ ions when they are in water)
React with compounds that contain carbonate
Are generally quite reactive
Turns litmus red
React with bases

3. Acids
Acids are widely used in industry, they are used in many manufacturing processes including; fertilizers, explosives, refining oil, and electroplating materials.

4. Table 1 : Examples of common acids
Common name
Formula
Source or use
Vinegar (acetic acid)
HC2H3O2
Salad dressing
Citric acid
HC6H7O7
Oranges, lemons
Ascorbic acid
HC6H7O6
Vitamin C
Lactic acid
HC­3H5O3
Sour milk or tired muscles
Sulfuric acid
H2SO4
Car batteries

5. Base
A base is most commonly thought of as an aqueous substance with a pH higher than 7.0 at standard conditions. They also:
Taste bitter
Are good conductors of electricity (They release OH- ions when dissolved in water)
Break down proteins into smaller molecules
May also be called alkaline
Turns litmus blue
React with acids

6. Table 2 Examples of some common bases
Common Name
Formula
Source or use
Sodium hydroxide
NaOH
Drain cleaner
Potassium hydroxide
KOH
Soap, cosmetics
Aluminum hydroxide
Al(OH)­3
Antacids
Ammonium hydroxide
NH­­4OH
Window cleaner.

7. pH
The pH scale is used to represent how acid or basic a solution is. The scale ranges from 0-14 with very acidic being 0, neutral being 7, and very basic being 14.

8. pH

9. Chemical Changes with Acids and Bases
Yeast is called a raising agent. The carbon dioxide it produces “raises” the bread and makes it lighter. Baking powder is another type raising agent. Baking powder is often used in making cakes and cookies because it works fast than yeast.

10. Baking soda is a base.
Vinegar is an acid.
Mixing them together produces a bubbling action. Baking powder releases carbon dioxide in the same way.

11. Ingredients:
Cream of tartar (acid)
Baking soda (base)
Corn starch (filler)

12. The filler keeps the acid and base separated
The filler keeps the acid and base separated. The filler also absorbs any moisture that might get into the baking powder. When you add a liquid such as water to baking powder, the dry acid and dry base dissolve. The acid and base react to produce carbon dioxide bubbles.

13. Questions: What is baking powder used for?
Why is corn starch added to baking powder?
Why isn’t vinegar used as the acid in baking powder?

14. Raising Agent Lab Question
Which raising agent produces carbon dioxide the fastest?
Safety precautions
Clean up the work area and wash your hands thoroughly at the end of the activity.
Never eat anything that has been made in a science room

15. Experimental Design
Use the tape and pencil to label the three beakers: baking soda, vinegar, and baking powder.
Add raising agent to its cylinder
Add 25 mL of egg white solution to each cylinder
Swirl each cylinder gently to mix
Measure the height of the foam in each cylinder every three minutes for 9 minutes
Record the results in the table.