November 16th, 2012
Competency
2b
Name: ____________________________________ Period: ____
Predict the properties and interactions of given elements using the
periodic table of the elements. (DOK 2)
8th – Lesson 1.11 SWBAT compare acids and bases and describe the pH scale.
Unit 1 – Chemistry: Acids and Bases
Quick Review of Molecules and Chemical Formulas:
1. Number of oxygen atoms in 3H2SO4 = 12
2. Number of hydrogen atoms in 3H2SO4 = 6
3. 12 molecules which each have 2 bromine atoms, 4 oxygen atoms, and one chlorine
atom = 12Br2O4Cl
4. Using the balanced chemical equation of 3KBr + Fe(OH)3 → 3KOH + FeBr3, atoms of
FeBr3 produced if 150 molecules of KBr are used = 50 molecules of FeBr3
Daily Question: What is the difference between an acid and a base?
Key Points on Acids and Bases:
1. In a normal atom, there are an equal number of negatively charged electrons and
positively charged protons = the atom has a neutral charge.
a. Sometimes atoms gain an electron, making the whole atom negatively
charged. (Remember, the atom is gaining a negative electron…it’s getting
MORE negative).
b. Sometimes atoms lose an electron, making the whole atom positively charged.
(Remember, the atom is losing a negative electron…it’s getting LESS negative)
2. An atom that has a positive or negative charge = ion
3. Acids: release H+ ions when dissolved in water.
a. Taste sour
b. React with metals to produce hydrogen gas
c. Examples: orange juice, vinegar, lemon juice, battery fluid
4. Bases: release OH- ions when dissolved in water.
a. Taste bitter
b. Feel slippery
c. Examples: soap, baking soda
d. Substances that are bases are also called basic or alkaline substances.
5. Both acids and bases
a. Corrosive: can cause burns, or “eat through” material like clothes.
b. Conduct electricity when mixed with water.
6. To measure the strength of acids and bases = pH scale
a. The pH scale ranges from 0-14
 pH of 7 = neutral
 pH less than 7 = acidic
 pH greater than 7 =
basic
b. The closer to 0 a solution is,
the stronger the acid.
c. The closer to 14 a solution is,
the stronger the base.
November 16th, 2012
Competency
2b
8th – Lesson 1.11
Name: ____________________________________ Period: ____
Predict the properties and interactions of given elements using the
periodic table of the elements. (DOK 2)
SWBAT compare acids and bases and describe the pH scale.
Acids and Bases
Quick Review of Molecules and Chemical Formulas:
1. Number of oxygen atoms in 3H2SO4 =
2. Number of hydrogen atoms in 3H2SO4 =
3. 12 molecules which each have 2 bromine atoms, 4 oxygen atoms, and one chlorine atom =
4. Using the balanced chemical equation of 3KBr + Fe(OH)3 → 3KOH + FeBr3, atoms of FeBr3
produced if 150 molecules of KBr are used =
molecules of FeBr3
Daily Question:
Key Points on Acids and Bases:
1. In a normal atom, there are an equal number of
charged electrons and
charged protons = the atom has a
charge.
a. Sometimes atoms
an electron, making the whole atom
charged. (Remember, the atom is gaining a negative electron…it’s getting
MORE negative).
b. Sometimes atoms
an electron, making the whole atom
charged. (Remember, the atom is losing a negative electron…it’s getting LESS
negative)
2. An atom that has a positive or negative charge =
3.
: release
ions when dissolved in
.
a. Taste
b. React with
to produce
gas
c. Examples: orange juice, vinegar, lemon juice, battery fluid
4.
: release
ions when dissolved in
.
a. Taste
b. Feel
c. Examples: soap, baking soda
d. Substances that are bases are also called
or
substances.
5.
acids and bases
a.
: can cause burns, or “eat through” material like clothes.
b. Conduct
when mixed with water.
6. To measure the
of acids and bases =
a. The pH scale ranges from 0-14
b. pH of
=
 pH
than 7 =
 pH
than 7 =
c. The closer to
a solution is, the
the acid.
d. The closer to
a solution is, the
the base.
November 16th, 2012
Name: ____________________________________ Period: ____
Demonstration: Acid and Base Indicator
Solution
A
B
C
D
Chemical Formula
CH3COOH (acetic acid)
C6H8O7 (citric acid)
pH reading
What do you think is in the solution?
NaClO (sodium hypochlorite)
Acids and Bases: Guided Practice
1. Fill in the table below and place the substances on the pH scale on the front of the page.
Acid or Base
Substance
pH
Battery Acid
1.0
Soda
3.3
Human Blood
7.4
Seawater
8.0
Soap Solution
10.0
Acids and Bases: Independent Practice
1. Key Point #1: How many protons and electrons are found in a normal carbon atom?
2. Key Point #1a: If an oxygen atom gains an electron, what will its charge be?
3. Key Point #1b: If a sodium atom loses an electron, what will its charge be?
4. Key Point #2: What would the two atoms in #2 and #3 be referred to as?
5. Key Point #3: If a substance reacts with copper metal releasing hydrogen gas and produces
hydrogen ions in water, what type of substance is it?
6. Key Point #4: If a substance feels slippery and produces hydroxide ions in water, what type of
substance is it?
7. Key Point #5: What type of substance is corrosive and conducts electricity when mixed with
water?
8. Key Point #6: Fill in the blanks below.
If a substance has a pH less than
it is considered an acid. If it has a pH greater than
that, the substance is
. HCl is a strong acid so its pH will be
than
the pH of a weaker acid or a base. Pure water and other substances that contain no acid or
base are considered
and have a pH of .