DO NOW
 You must be silent
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

and working for
credit
Be on time
Enter silently
Grab papers
Immediately start
work
No talking
1. How many days until
we reach our big goal?
2. Why will it be
important for us to
know what kind of soil
sample was left at the
crime scene?
3. Since we now know that
it was window glass and
cotton fabric, which
suspect do you think it
was?
Today’s Objectives
 SWBAT define and characterize an acid.
 SWBAT define and characterize a base.
 SWBAT describe pH scale used to classify acids and
bases.
SPI 3221.3.7: Classify substances as acids or
bases based on their formulas and how they
react with various indicators.
Reminder of Expectations
 If the notes on the PowerPoint are in red, you must
copy it down
 Notes are a silent activity so you can hear my
explanations and we can move through them quickly

 You’ll need two pieces of paper today – one for notes,
and one for “check-ins” on today’s lesson (which will
be turned in)
 The blank paper you got on your way in is for
independent practice, so don’t use it now!
The Chemistry of Acids
and Bases
!
Acid and Bases
Acid and Bases
Acid and Bases
Some Properties of Acids
Produce H+ (as H3O+) ions in water (the hydronium ion is a
hydrogen ion attached to a water molecule)
Taste sour
Corrode metals
React with bases to form a salt and water
pH is less than 7
Turns litmus paper to red
QUICK CHECK
2nd piece of paper
 If the pH is above 7, is it an acid?
 What kind of ions do acids produce?
 What do acids taste like?
Some Common Acids
 Hydrochloric acid (HCl) in gastric juice
 Sulphuric acid (H2SO4)
 Nitric acid (HNO3)
 Carbonic acid in softdrink (H2CO3)
 Uric acid in urine
 Ascorbic acid (Vitamin C) in fruit
 Citric acid in oranges and lemons
 Acetic acid in vinegar
 Tannic acid (in tea and wine)
 Tartaric acid (in grapes)
Notice something
about the formulas for
acids?
Some Properties of Bases
 Produce OH- ions in water
 Taste bitter, chalky
 Feel soapy, slippery
 React with acids to form salts and water
 pH greater than 7
 Turns litmus paper to blue: “Basic Blue”
QUICK CHECK
2nd piece of paper
 What do bases taste like?
 What is the pH if something is a base?
 What color is litmus paper if you dip it in a base?
Some Common Bases
NaOH
sodium hydroxide
lye
KOH
potassium hydroxide
liquid soap
Ba(OH)2
barium hydroxide
stabilizer for plastics
Mg(OH)2
magnesium hydroxide “MOM” Milk of magnesia
Al(OH)3
aluminum hydroxide
Maalox (antacid)
Notice something
about the formulas for
bases?
The pH scale is a way of
expressing the strength of acids
and bases.
Under 7 = acid
7 = neutral
Over 7 = base
The lower the number, the
stronger the acid, the higher
the number, the stronger the
base
pH of Common Substances
Check for Understanding
2nd piece of paper
Choose acid or base for the following:
1. pH=12
2. Bitter taste
3. Has an H+ group
4. Slippery
5. pH=2
6. Which is stronger, an acid with pH 4, or a pH 1?
7. Corrosive on metals
8. Has an OH- group
INDEPENDENT PRACTICE
 Draw your own pH scale using the following points.
Make sure to label the acid and base side Be sure to draw
a picture of the object near it on the scale – MAKE IT
BEAUTIFUL!
pH = 7 (water)
pH = 8.2 (baking soda)
pH = 2.5 (lemonade)
pH = 11 (laundry detergent)
pH = 1.5 (stomach acid)
pH = 10 (windex)
pH = 14 (lye)  used to make soap
You may work with
pH = 4 (coca-cola)
a partner, IN A
SEAT,
WHISPERING
EXIT TICKET
Based on the pH of the following substances, tell
me if they are an acid or a base:
a. pH of 4
b. pH of 11
c. pH of 7.8
d. pH of 1
2. Which is a stronger acid, something with a pH of 2
or a pH of 5?
1.