Chapter 2: Antacids
Antacids
This chapter will introduce the chemistry
needed to understand how antacids work
Section 2.1: Types of Matter
Section 2.2: Naming Chemicals
Section 2.3: Writing Formulas
Section 2.4: Acids & Bases
Section 2.5: Chemical Reactions
Section 2.6: Balancing Chemical Equations
Section 2.7: Speeding up Chemical Reactions
Intro—Antacids
Why do we need antacids?
Your body needs hydrochloric acid to
digest food
Too much causes heartburn, ulcers and
can damage your esophagus
Antacids versus Acid Inhibitors
There are two types of medicines you can use
Antacids
Acid Inhibitors
Neutralizes the acid currently
in your system
Controls the amount of acid
your body produces
Work quickly but your body
will make more acid again
Long-term solution, but
needs to build up in your
system to be most effective
Alka-Seltzer ®, Rolaids ®,
Tums ®, Malox ®, Mylanta ®
Tagamat ®, Zantac ®, Pepcid
AC ®
Is it fair when a commercial compares the fast action of an antacid to an
acid inhibitor that takes up to 7 days to build up?
Section 2.1—Types of Matter
Matter is….
Anything that has mass and takes up
space (volume)
Anything made from atoms
Examples: elements, molecules, cells,
people, air, water, paper
Non Examples: dreams, energy (light,
heat), emotions
Pure Substances versus Mixtures
Matter is classified as either a pure substance or a mixture
Pure Substances
Contain only 1 type of
particle
Elements or
Compounds
Mixtures
Contain 2 or more
pure substances
Homogeneous or
Heterogeneous
Pure Substances
Elements
Simplest kind of
matter
Made of only 1 kind
of atom
Cu, Ag, Fe, Br2
Compound
2 or more
elements
chemically bonded
together to form
molecules. Each
is the same fixed
ratio of elements.
H2O, NaCl, CO2
Elements
Single Atom
Element
Cannot be separated by
chemical or physical
processes
Pure substance
Every atom is the same
Elements can be found on the periodic table!
Elements
http://www.youtube.com/watch?v=7FesjAdIWBk
Compounds
Single Molecule
Made of more than one type of
atom bonded together
Compound
Pure substance
Every molecule is the same
Can only be separated by chemical
reactions
Mixtures
More than 1
different type
of matter
Mixture
Not a pure substance
Physical combination of more
than 1 type of pure substance
Can be separated
physically by
 Distillation
 Filtration
 Chromatography
Mixtures
Mixtures can be classified as homogeneous or heterogeneous
Homogeneous
(aka “solution”)
It looks the same
throughout;
substances evenly
dispersed
Ex. salt water,
alloys, clean air
Heterogeneous
Different substances
can be seen (chunks,
bubbles, floaties,
layers)
Ex. salad dressing,
fog, chocolate chip
cookies, soil
Mixture possibilities
Mixtures can be any combination of solids,
liquids and gases:
Solid-solid: Medicine tablet
Solid-gas: Pop Rocks candy
Solid-liquid: Ice water
Liquid-liquid: lemon water
Gas-Liquid: Carbonated water
Gas-Gas: Air
Homogeneous Mixtures
Kool-Aid: sugar in water
Brass: copper in zinc
Air: oxygen gas in nitrogen gas
Milk: fat, proteins, sugar in water
Heterogeneous Mixtures
Oil in water
Italian Salad Dressing
Chicken Noodle Soup
Fruit Salad
Classification of Matter
True Solutions, Colloids & Suspensions
Homogeneous
Heterogeneous
True Solution
Colloid
particles
don’t settle out
and are too small
to scatter light
Ex: salt water, air,
brass
INTERMEDIATE
SMALL
particles don’t
settle out but are
large enough to
scatter light:
Ex: fog, foam,
jello, paint
Dissolved Particle Size Increases
Heterogeneous
Suspension
LARGE particles
that settle out
over time
Ex: oral
medicines, italian
dressing, paint
True Solutions
Suspensions
vinegar and oil salad dressing
Particles Scattering Light
If the dissolved particles
are large enough to scatter
light, we say it exhibits the
“Tyndall Effect”
Solution
Light passes through unchanged
Colloids exhibit the Tyndall Effect
Light is scattered by larger solute
particles
Connect these concepts with Antacids
What type of matter do you think antacids
are?
Pure substance (Element or compound)
Mixture (homogeneous or heterogeneous)
Connect these concepts with Antacids
Antacids are mixtures.
They contain active & inactive ingredients
What purposes could the inactive
ingredients serve?
Connect these concepts with Antacids
Inactive ingredients might
Add volume to make the pill able to be handled
Add color and flavor
Allow the tablet to be compressed and formed
Let’s Practice: Not in Notes
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Tin can (Sn)
Copper pipe (Cu)
Concrete
Carbon tetrachloride(CCl4)
Sports drink
Let’s Practice
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Tin
Element
Copper pipe
Element
Concrete
Heterogeneous mix
Carbon tetrachloride
Compound
Sports drink
Homogenous mix
You Try! In Notes
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Aluminum foil (Al)
Water (H2O)
soda
soil
Carbon dioxide(CO2)
Tap water
You Try!
Example:
Determine if
each is
element,
compound,
homogeneous
or
heterogeneous
mixtures
Aluminum foil (Al)
Element
Water (H2O)
Compound
Flat soda
Homogeneous mix
soil
Heterogeneous mix
Carbon dioxide(CO2)
compound
Tap water
Homogeneous mix
The Science of Macaroni Salad
http://www.freetech4teachers.com/2013/08/t
he-science-of-macaronisalad.html#.UkySCODvSDo
Section 2.2—Naming
Chemicals
We need to be able to name the chemicals in the antacids!
The Language of Chemistry
Chemistry has a language all of its own
Chemistry
English
Element Symbols
Letters
Chemical Formulas
Words
Chemical Equations
Sentences
Each element symbol starts with a capital letter
ELEMENTS: made of atoms
An atom consists of subatomic particles
There are 3 subatomic particles: protons,
electrons and neutrons
Neutral atoms have the same number of
protons and eletrons
IONS
An atom or group of atoms with a charge.
The number of protons does not equal the
number of electrons.
WHY? Atoms can gain or lose electrons to
acquire stability like a noble gas element.
The Periodic Table of Elements
Metals form cations
NonMetals form anions
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
Lu
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Lr
Rf
Db
Sg
Bh
Hs
Mt
Uun
Uuu
Uub
Uut
Metals
Metalloids
Nonmetals
Monatomic Ions (formed from a single atom)
Cations
Positive charge
Metal atoms that lose electrons
Group A (Representative metals/Type I )
The group # for metals in columns 1A, 2A, & 3A
is equal to the charge of the cation
Naming them: Take the element name and
add the word ion
Monatomic Ions of Group A /Type I
Metals
Group A
Group A
Group B
Group B (Transition/Type II Metals): have
more than one charge
You should be familiar with the following
transition metals with more than one
charge.
Naming them: Take
Fe+2
Fe+3
the element name
Sn+2
Sn+4
and place in
+2
+4
Pb
Pb
parentheses
the
Co+2
Co+3
charge number as a
Cr+2
Cr+3 roman numeral and
Mn+2
Mn+3 add the word ion
Cu+1
Cu+2
Monatomic Ions of Transition/Type II
Metals
+
Monatomic Ions (formed from a single
atom) Cu+2, F-1
Anions
Negative charge
Nonmetals that gain electrons
Group A (Representative nonmetals)
Subtract the group # in columns 4A, 5A, 6A,
and 7A from 8 to get the charge.
Naming them: Drop the ending of the element
and add –ide and then ion
You Try!
Try These: Write the formula for each ion
and name it.
 Calcium
 Chromium
 Chlorine
 Sulfur
You Try!
Try These: Write the formula for each ion and
name it.
 Calcium
Ca+2 calcium ion
 Chromium
Cr+2 chromium(II) ion
Cr+3 chromium (III) ion
Chlorine
Cl-1 chloride ion
 Sulfur
S-2 sulfide ion
Self Check
Try These: Write the formula for each ion
and name it.
+3 Aluminum Ion
Al
 Aluminum
+2 Zinc ion
Zn
 Zinc
Fe+2 Iron (II) ion or
 Iron
Fe+3 Iron (III) ion
 Phosphorus P-3 Phosphide ion
Binary Ionic Compounds
Binary Ionic Compound- compound
containing 2 elements—one metal and
one non-metal
The atoms are held together by Ionic Bondsbond formed by attraction between + ions and –
ions
Metal
Nonmetal
+
Cation
Anion
Ionic Compound
Metals & Non-Metals
Ionic Bonds are between metals & non-metals
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
Lu
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Lr
Rf
Db
Sg
Bh
Hs
Mt
Uun
Uuu
Uub
Uut
Metals
Metalloids
Nonmetals
How to Identify & Name a Binary
Ionic Compound
Look for:
2 elements (“binary”)
A type I metal & a non-metal (“ionic”)
To name these compounds:
Write the name of the type 1 metal (the cation)
Write the name of the non-metal (the anion) with
the suffix “-ide”
The subscripts in the formula do not matter when naming this type
Example #1
NaCl
“Sodium”
Cation
NaCl
Anion
“Chlorine” becomes
“Chloride”
Sodium Chloride
Example #2
CaBr2
“Calcium”
Cation
CaBr2
Anion
“Bromine” becomes
“Bromide”
Calcium Bromide
Example #3
K2O
“Potassium”
Cation
K2O
Anion
“Oxygen” becomes
“Oxide”
Potassium Oxide
Self Check
Li2O
Example:
Write the name
for the following
compounds
Sr3P2
MgS
BaI2
Answers
Example:
Write the name
for the following
compounds
Li2O
Lithium oxide
Sr3P2
Strontium phosphide
MgS
Magnesium sulfide
BaI2
Barium iodide
Ternary Ionic Compounds
Ternary Ionic Compound- a compound
containing at least one polyatomic ion
Polyatomic Ion- an ion that has more than one
atom that together have a single charge
+
Cation
+
Polyatomic
Cation
- Polyatomic
Anion
Anion
Ternary Ionic
Compound
Common Polyatomic Ions
You don’t need to memorize them. Look at your reference
sheet.
COMMON POLYATOMIC IONS
Acetate, CH3COO-1 or C2H3O2-1
Ammonium NH4+1
Bromate, BrO3-1
Bromite, BrO2-1
Carbonate, CO3-2
Carbonite, CO2-2
Chlorate, ClO3-1
Chlorite, ClO2-1
Chromate, CrO4-2
Cyanide, CN-1
Dichromate, Cr2O7-2
Dihydrogen phosphate, H2PO4-1
Hydrogen carbonate or bicarbonate, HCO3-1
Hydrogen phosphate or biphosphate, HPO4-2
Hydrogen sulfate or bisulfate, HSO4-1
Hydroxide, OH-1
Hypochlorite, ClO-1
Iodate, IO3-1
Iodite, IO2-1
Nitrate, NO3-1
Nitrite, NO2-1
Oxalate, C2O4-2
Perchlorate, ClO4-1
Permanganate, MnO4-1
Peroxide, O2-2
Phosphate, PO4-3
Phosphite, PO3-3
Silicate, SiO3-1
Sulfate, SO4-2
Sulfite, SO3-2
Identifying Polyatomic Ions: Hints
The only cation (front-half) polyatomic ion
is “NH4+”
All other polyatomic ions are anions (backhalf)
The subscripts within the polyatomic ion
are important (it must match exactly with
the one on your ion list)
If there are parentheses, the polyatomic ion
is inside (ignore the number outside)
Practice Identifying Polyatomic Ions
Example:
Underline&
name the
polyatomic ion
in each
compound
NaNO3
NH4Cl
Ca(OH)2
(NH4)3PO4
K2CO3
Practice Identifying Polyatomic Ions
Example:
Identify and
name the
polyatomic ion
in each
compound
NaNO3
Nitrate
NH4Cl
Ammonium
Ca(OH)2
Hydroxide
(NH4)3PO4
Ammonium &
phosphate
K2CO3
Carbonate
How to Identify & Name Ternary Ionic
Compounds
Look for:
More than 2 capital letters next to one another
(not starting with H)
Contain at least 1 metal & 1 non-metal
To name these compounds:
Write the name of the cation (either the metal
element name or “Ammonium” for “NH4+”)
If the anion is a polyatomic ion, write the given
polyatomic ion’s name
If the anion is a single non-metal element, write
its name with the suffix “-ide”
Example # 4
Ca(NO3)2
“Calcium”
Cation
Ca(NO3)2
Polyatomic
Anion
“Nitrate”
Calcium Nitrate
Example #5
Na3PO4
“Sodium”
Cation
Na3PO4
Polyatomic
Anion
“phosphate”
Sodium phosphate
Example # 6
K2CO3
“potassium”
Cation
K2CO3
Polyatomic
Anion
“carbonate”
Potassium carbonate
Self Check
Ca(C2H3O2)2
Example:
Write the name
for the following
compounds
Li2SO3
Ba(OH)2
(NH4)2S
Answers
Ca(C2H3O2)2 Calcium acetate
Example:
Write the name
for the following
compounds
Li2SO3
Lithium sulfite
Ba(OH)2
Barium hydroxide
(NH4)2S
Ammonium Sulfide
Worksheet 1 (1-10 Answers)
1. Sodium sulfide
6. Silver chloride
2. Aluminum oxide
7. Boron nitride
3. Sodium chloride
8. Barium fluoride
4. Rubidium iodide
9. Strontium nitride
5. Zinc bromide
10. Magnesium chloride
Worksheet 2 (1-10 Answers)
1. copper(I) fluoride
6.chromium (VI) oxide
2. copper (II) fluoride
7. gold(I) bromide
3. chromium (III)
oxide
8. nickel(II) oxide
4. lead (II) iodide
10. tin(IV) oxide
5. lead (IV) chloride
9. vanadium(III) iodide
Worksheet 3 (1-10 Answers)
1. vanadium(V)
chlorate
2. rhenium(VI)
sulfate
3. osmium(III) iodate
4. iridium(IV)
phosphate
5. palladium(IV)
sulfite
Gold(I) nitrate
7. iron(III) phosphite
8. nickel(II) bromate
9. lead(IV) sulfide
10. Manganese (VII)
dichromate
Worksheet 4 (1-10 Answers)
1. ammonium chloride 6. ammonium nitrate
2. hydrogen chlorite
7. strontium phosphate
3. calcium bromate
8. zinc chlorate
4. beryllium sulfate
9. silver iodate
5. ammonium nitride 10. potassium dichromate
Transition Metals Revisisted
Transition Metal- group “B” or Type II metal that has
the possibility of having more than one cation charge;
Common multivalent metals and their charges
Cobalt
Copper
Iron
Manganese
Mercury
Co+2
Cu+1
Fe+2
Mn+2
Hg2+2
Co+3
Cu+2
Fe+3
Mn+3
Hg+2
IMPORTANT:
Although group B metals, SILVER (+1), CADMIUM (+2), and ZINC (+2) only
have 1 charge
Although the elements of TIN and LEAD are group A elements, they do
have more than one charge
Sn(+2 and +4)
and Pb(+2 and +4)
How to Identify & Name Ionic
Compounds with Transition Metals
 Look for:
One of the transition metals, excluding Ag, Cd, and Zn
 To name these compounds:
Write the name of the Type II metal element (cation)
Write the name of the anion (element name with “-ide” or
polyatomic ion name)
Determine the charge of the transition metal
1. Total negative charge = total positive charge for all
neutral compounds
2. Divide total positive charge by the number of metal
atoms
3. Write the charge in roman numerals in parentheses after
the Type II metal’s name
Example # 7
CuCl
“Copper”
Cation
CuCl
Anion
“Chlorine”
becomes
“Chloride”
Copper
Chloride
“Copper”
Cation
Chloride has a –1 charge
CuCl
Anion
“Chlorine”
becomes
“Chloride”
-1 charge * 1 ion = -1
A –1 charge needs a +1 charge
Therefore, copper must be +1, (I)
Copper (I) Chloride
Example # 8
Fe2(CO3)3
“Iron”
Cation
Fe2(CO3)3
Polyatomic
Anion
“Carbonate”
Iron
carbonate
“Iron”
Cation
Carbonate has a –2 charge
Fe2(CO3)3
Polyatomic
Anion
“Carbonate”
-2 charge * 3 ions = -6
A –6 charge needs a +6 charge
and there are 2 iron ions
Therefore, iron must be +3 (III)
Iron (III) carbonate
Example # 9
ZnBr2
“Zinc”
Cation
ZnBr2
monatomic
Anion
“bromide”
Zinc
bromide
“Zinc”
Cation
bromide has a –1 charge
ZnBr2
Polyatomic
Anion
“bromide”
-1 charge * 2 ions = -2
A –2 charge needs a +2 charge
and there is 1 zinc ion
Therefore, zinc must be +2 (not
needed) it only has one charge
Zinc bromide
Self Check
PbCl2
Example:
Write the name
for the following
compounds
PbCl4
MnO
Mn2O3
Answers
Example:
Write the name
for the following
compounds
PbCl2
Lead (II) chloride
PbCl4
Lead (IV) chloride
MnO
Manganese (II) oxide
Mn2O3
Manganese (III) oxide
Binary Covalent (Molecular)
Compounds
Binary Molecular Compounds are made
from two non-metals that are covalently
bonded
Covalent bond a bond formed from atoms
that share electrons
Non
metal
Non
metal
Covalent compound
Identifying & Naming Binary Molecular
These compounds have:
2 elements (“binary”)
Both non-metals (“covalent”)
To name these compounds:
Write the name of the first element with the
prefix indicating the number of atoms (except
don’t use “mono-” if only 1 atom)
Write the name of the second element with the
prefix indicating the number of atoms (including
“mono-”) and the suffix “ide”
Covalent Prefixes
PREFIXES USED IN MOLECULAR COMPOUNDS
1. mono
2. di3. tri4. tetra5. penta6. hexa7. hepta8. octa9. nona10.deca-
Example #10
P2O5
2 = “di-”
Phosphorus
P2O5
Oxygen
5 = “penta-”
“oxide”
Diphosphorus pentaoxide
Example #11
SiF4
Don’t use “mono-” on
first element
Silicon
SiF4
Fluorine
4 = “tetra-”
“fluoride”
Silicon tetrafluoride
Self Check
SO2
Example:
Write the name
for the following
compounds
N2Cl4
P4O10
CO
Answers
Example:
Write the name
for the following
compounds
SO2
sulfur dioxide
N2Cl4
Dinitrogen tetrachloride
P4O10
Tetraphosphorus decaoxide
CO
Carbon monoxide
Mixed Practice: Determine the type of
compound, Ionic (m/nm) or Covalent (nm/nm)
& then follow rules
Na2O
Example:
Write the name
for the following
compounds
K3PO4
Cu(OH)2
N2S
MgCl2
Answers
Example:
Write the name
for the following
compounds
Na2O
Sodium oxide
K3PO4
Potassium phosphate
Cu(OH)2 Copper (II) hydroxide
N2S
Dinitrogen monosulfide
MgCl2
Magnesium chloride
Section 2.3—Writing Chemical
Formulas
We need to be able to read the formulas for chemicals in
the antacids!
Reminders from Section 2.2
Your Reference sheet has a list of:
Common polyatomic ions
Use your periodic table is used to
determine the charges of common
elements when they form ions
You must memorize the 10 prefixes for
covalent compounds
Binary Ionic Compounds
 containing two elements—one
metal and one non-metal
 formed by attraction between + and ions
+
Cation
Anion
Ionic Compound
How to Write Formulas for Binary
Ionic Compounds
 These compounds:
End in “-ide” (except “hydroxide and cyanide”)
Do NOT contain covalent prefixes
 To write these formulas:
Write the symbol & charge of the first element (the metal,
cation)
Write the symbol & charge of the second element (the
non-metal, anion)
Add more of the cations and/or anions to have a neutral
compound
Use subscripts to show how many of each type of ion is
there.
Example #1
Sodium chloride
Na+1
Cation
Sodium chloride
Anion
Cl-1
NaCl
Example #1
Na+1
Cation
Na+1Cl-1
Sodium chloride
Anion
Cl-1
NaCl
+1 + -1 = 0
The compound is neutral…no
subscripts are needed.
Example #2
Calcium bromide
Example #2
Ca+2
Cation
Calcium bromide
Anion
Br-1
Example #2
Ca+2
Cation
Ca+2 Br-1
Calcium bromide
Anion
Br-1
CaBr2
+2 + -1 = +1
Ca+2 Br-1 Br-1
+2 + -1 + -1 = 0
The subscript “2” is used to show
that 2 anions are needed.
A Simple Method to Writing Binary
Ionic Formulas
 The Criss - Cross Method:
Write the symbol & charge of the first element (the metal,
cation)
Write the symbol & charge of the second element (the
non-metal, anion)
Cross ONLY the charge numbers down diagonally to
make subscripts IF they are not equal to each other
Simplify subscripts if you can
Ca +2 Br-1  Ca1Br2 
1
2
CaBr2
Self Check
Cesium chloride
Example:
Write the
following
chemical
formulas
Potassium oxide
Calcium sulfide
Lithium nitride
Answers
Example:
Write the
following
chemical
formulas
Cesium chloride
CsCl
Potassium oxide
K2O
Calcium sulfide
CaS
Lithium nitride
Li3N
Ternary Ionic Compounds
 compound containing at least one
polyatomic ion
 Either in the front, the back or in both
places
+
Cation
Polyatomic
Anion
Polyatomic Ionic
Compound
How to Identify & Name Ternary Ionic
Compounds
 These compounds:
Do not end with “-ide” (except hydroxide & cyanide)
Do not use covalent prefixes
 To write these formulas:
Write the symbol & charge of the cation & anion
Add additional cations or anions to have a neutral compound
Use subscripts to show the number of ions
When using subscripts with a polyatomic ion,
you must put the polyatomic ion in a
parenthesis with the subscript on the
outside
Example #3
Sodium carbonate
Na+1
Cation
Sodium carbonate
Polyatomic
Anion
CO3-2
Na+1
Cation
Na1+ CO32-
Sodium carbonate
Polyatomic
Anion
CO3-2
Na2CO3
+1 + -2 = -1
Na+ Na+ CO32+1 + 1 + -2 = 0
The subscript “2” is used to show
that 2 cations are needed.
Example #4
Magnesium nitrate
Mg+2
Cation
Magnesium nitrate
Polyatomic
Anion
NO3-1
Mg+2
Mg+2NO31-
Cation
+2 + -1 = 1
Magnesium nitrate
Mg+2 NO3- NO3-
Polyatomic
Anion
NO3-1
Mg(NO3)2
+2 + -1 + -1 = 0
The subscript “2” is used to show
that 2 anions are needed.
Use parenthesis when adding
subscripts to polyatomic ions
Self Check
Sodium nitrate
Example:
Write the
following
chemical
formulas
Calcium chlorate
Potassium sulfite
Calcium hydroxide
Answers
Example:
Write the
following
chemical
formulas
Sodium nitrate
NaNO3
Calcium chlorate
Ca(ClO3)2
Potassium sulfite
K2SO3
Calcium hydroxide
Ca(OH)2
Transition Metals
 metal that has more than one
possibility for cationic charge
How to Identify & Name Ionic
Compounds with Transition Metals
These compounds:
Will have roman numerals
To write these formulas:
Same as binary ionic or polyatomic ionic.
The roman numerals tell the charge of the
metal (cation)
Example #5
Iron (III) oxide
Fe+3
Cation
Iron (III) oxide
Anion
O-2
Fe+3
Fe+3 O2-
Cation
Iron (III) oxide
+3 + -2 = -1
Fe+3 Fe+3 O2- O2-
Anion
+3 + 3 + -2 + -2 + -2 = 0
O-2
Fe2O3
The subscript “2” and “3” are
used to show the numbers of
atoms needed.
Example #6
Copper (II) nitrate
Cu+2
Cation
Copper (II) nitrate
Polyatomic
Anion
NO3-1
Cu+2
Cu+2 NO31-
Cation
Copper (II) nitrate
+2 + -1 = 1
Cu+2 NO3- NO3-
Polyatomic
Anion
+2 + -1 + -1 = 0
NO3-1
Cu(NO3)2
Use parenthesis when adding
subscripts to a polyatomic ion
Self Check
Iron (II) nitrate
Example:
Write the
following
chemical
formulas
Copper (I) chloride
Lead (IV) hydroxide
Tin (II) oxide
Answers
Example:
Write the
following
chemical
formulas
Iron (II) nitrate
Fe(NO3)2
Copper (I) chloride
CuCl
Lead (IV) hydroxide
Pb(OH)4
Tin (II) oxide
SnO
Binary Covalent Compounds
 compound made from two nonmetals
 between atoms that share electrons
Non
metal
Non
metal
Covalent compound
How to Identify & Name Binary
Covalent Compounds
These compounds:
Use covalent prefixes
To write these formulas:
Write the symbols of the first and second
element
Use the covalent prefixes (assume the first
element is “1” if there’s no prefix) as the
subscripts to show number of atoms.
Atoms do not form charges when bonding covalently…you DO NOT
need to worry about charges with this type! NOR CRISS CROSS
METHOD!
Example #7
Dinitrogen Tetraoxide
“Di-” = 2
N
Dinitrogen Tetraoxide
O
“Tetra-” = 4
N2O4
Example #8
Silicon dioxide
“Mono-” is not written for
the first element
Si
Silicon dioxide
O
“Di-” = 2
SiO2
CAUTION!!!
“di” and “bi” do not mean the same thing!
di-
bi-
Stands for “2” in covalent
compounds
Means there’s a hydrogen in
the polyatomic anion
Carbon dioxide = CO2
Sodium biphosphate =
Na2HPO4
Self Check
Carbon monoxide
Example:
Write the
following
chemical
formulas
Sulfur tetraiodide
Trichlorine pentasulfide
Answers
Example:
Write the
following
chemical
formulas
Carbon monoxide
CO
Sulfur tetraiodide
SI4
Trichlorine pentasulfide Cl3S5
Self Check: Mixed Practice
Magnesium hydroxide
Example:
Write the
following
chemical
formulas
Copper (II) nitrate
Iron (III) oxide
Nitrogen dioxide
Sodium bicarbonate
Answers
Example:
Write the
following
chemical
formulas
Magnesium hydroxide
Mg(OH)2
Copper (II) nitrate
Cu(NO3)2
Iron (III) oxide
Fe2O3
Nitrogen dioxide
NO2
Sodium bicarbonate
NaHCO3
Section 2.4
We need to know how acids behave when
talking about ant-acids!
What is an Acid? – Arrhenius Definition
A substance that produces hydrogen ions
(H+1) when dissolved in water.
 H+1 immediately reacts with water to make the
hydronium ion, H3O+1
+1
+1
water
How do Acids produce Hydronium?
water
acid
Hydrogen cation with some anion
How do Acids produce Hydronium?
+1
-
How do Acids produce Hydronium?
+1
Hydronium ion
Anion
How to Identify an Acid
Look for a hydrogen ion, “H+” as the first
element in an aqueous covalent
compound.
H2SO4 HCl
H2CO3
HNO3
HC2H3O2
Naming Binary Acids: Non-Oxygen Acids
These compounds have to :
Start with “H” (more than 1 “H” is OK, too).
Do not contain oxygen
To name these compounds:
Use “hydro____ic acid”
Fill in the blank with the root of the anion’s
name
Example #1
HBr(aq)
It’s an acid
Hydrogen cation
HBr(aq)
Hydrobromic acid
Bromine
No oxygen
Use “hydro___ic”
Naming Oxyacids: contain oxygen
These compounds have:
Start with “H” (more than 1 “H” is OK, too).
Must contain oxygen
To name these compounds:
Use “___ic acids” for “-ate” anions
Use “___ous acids” for “-ite” anions
Do not use “hydro” with these…the word “acid” is how you know it
begins with hydrogen, not “hydro-”
Example #2
HNO2(aq)
It’s an acid
Hydrogen cation
HNO2(aq)
nitrite ion
“-ite” ion
Use “___ous” acid
Nitrous acid
Example #3
HC2H3O2(aq)
It’s an acid
Hydrogen cation
HC2H3O2(aq)
acetate ion
“-ate” ion
Use “___ic”
acetic acid
Self Check
HF
Example:
Write the name
for the following
acids
H2S
H3PO4
Answers
Example:
Write the name
for the following
acids
HF
Hydrofluoric acid
H2S
Hydrosulfuric acid
H3PO4
Phosphoric acid
Writing the chemical formula for
“Hydro-” acids
To write these formulas:
Write the cation, H+1
Write the anion symbol and charge
Balance the charges by adding the appropriate
subscript to the hydrogen cation OR Criss Cross
Method
Example #4
Hydrobromic acid
H+1
Hydrogen cation
Hydrobromic acid
Does not contain oxygen
Br-1
H+1
Hydrogen cation
Hydrobromic acid
Does not contain oxygen
Br-1
H+1Br-1
+1 + -1 = 0
HBr
The compound is neutral.
Subscripts are not needed
Writing chemical formulas for
“Oxyacids”
To write these formulas:
Write the cation H+1
If it is an “-ic” acid, determine the polyatomic ion
ending in “-ate”
If it is an “-ous” acid, determine the polyatomic
ion ending in “-ite”
Add subscript to the hydrogen cation to balance
charges OR use Criss Cross Method
Example #5
Carbonic acid
H+1
Hydrogen cation
Carbonic acid
From the “___ate” anion
CO3-2
H+1
Hydrogen cation
H+ CO32+1 + -2 = -1
Carbonic acid
From the “___ate” anion
CO3-2
H2CO3
H+ H+ CO32+1 + 1 + -2 = 0
Example #6
Chlorous acid
H+1
Hydrogen cation
chlorous acid
From the “___ite” anion
ClO2-1
H+1
Hydrogen cation
Chlorous acid
From the “___ite” anion
ClO2-1
H+ClO2-1
+1 + -1 = 0
HClO2
Self Check
Phosphorous acid
Example:
Write the
formula for the
following acids
Hydroiodic acid
Answers
Example:
Write the
formula for the
following acids
Phosphorous acid
H3PO3
Hydroiodic acid
HI
You Really Only Need to Know
These Acids! Memorize them!
Hydrochloric acid
Sulfuric acid
Carbonic acid
Nitric acid
Acetic acid
HCl
H2SO4
H2CO3
HNO3
HC2H3O2
What is a Base? – Arrhenius Definition
A substance that produces hydroxide
ions, OH-1 in water
H2O
NaOH(s)
Na+1(aq) + OH-1(aq)
+1
-1
Hydroxide Ion
water
How to Identify a Base
Look for an ionic compound that has a
metal paired with the hydroxide ion, “OH-”
OR Look for the ammonia molecule
NaOH
Ca(OH)2
NH3
**Do not assume all compounds ending in OH
are bases: CH3OH is not a base but an alcohol
Naming & Writing Formulas for Metal Hydroxides
Follow the rules for ionic compounds.
The most common exception to this is
ammonia, NH3
NH3 (ammonia) is a base even though it doesn’t
contain “-OH” as the anion
Example #7
NaOH
Sodium
NaOH
Hydroxide
Sodium Hydroxide
Self Check
Ca(OH)2
Example:
Write the
formula or
name for each
KOH
Copper (II) hydroxide
Lithium hydroxide
Answers
Example:
Write the
formula or
name for each
Ca(OH)2
Calcium hydroxide
KOH
Potassium hydroxide
Copper (II) hydroxide
Cu(OH)2
Lithium hydroxide
LiOH
What is an Acid according to
Bronsted-Lowry?
 Is a substance that is a proton or hydrogen
donor
Example: HCl + H2O  H3O+1 + Cl-1
acid
base
What is a base according to
Bronsted-Lowry?
 Is a substance that is a proton acceptor
Example: NH3 + H2O  OH- + NH4+
base
acid
conjugate conjugate
base
acid
Conjugate Acid-Base Pairs
 Conjugate Acid- substance formed when a base gains a [H+] ion.
 Conjugate Base- substance formed when an acid loses a [H+] ion.
Label the acid & base on the left side of the reaction & the conjugate
acid & conjugate base on the right side.
a) HNO3 + H2O  H3O+ + NO3−
acid
base ______
C.A. ______
______
______
C.B.
b) NH3 + H2O  NH4+ + OH−
_____
______
acid ______
C.B.
base
C.A. ______
Characteristics of Acids & Bases
Acids
Bases
Produce H3O+1 (hydronium
ion) in water
Produce OH-1 (hydroxide ion)
in water
Tastes sour
Tastes Bitter
React with active metals to
form hydrogen gas
Feels slippery
Neutralizes a base to form
salt and water
Neutralizes an acid to form
salt and water
Both forms ions when dissolved: conducts electricity: They are called
ELECTROLYTES
Strength versus Concentration
strong acid – ALL acid molecules separate
(dissociate) into [H+] ions in water; only ions
present
Examples: HCl, HNO3, H2SO4
 weak acid – Most acid molecules stay together,
only a FEW separate into [H+] ions when in water;
few ions present, mostly molecules
Examples: HC2H3O2 (vinegar) , H2CO3
Strong Acid
Weak Acid
Strong versus Weak Acids
-
-
How many hydronium ion – anion
pairs can you find?
3
+
-
How many intact acid molecules can
you find?
1
Strong acid
Most of the acid molecules
have donated the H+1 to water
Strong versus Weak Acids
How many hydronium ion – anion
pairs can you find?
+
1
How many intact acid molecules can
you find?
3
-
Weak acid
Only a few of the acid
molecules have donated the
H+1 to water
Strong Acids vs. Weak Acids
Concentrated versus Dilute
solute
solvent
DILUTE
(low concentration)
CONCENTRATED
(higher concentration)
Very little solute (what’s being
dissolved) particles in solution
Lots of solute (what’s being
dissolved) particles in solution
Combinations of Concentration & Strength
Concentrated
Dilute
Strong
A lot of
acid/base added
& all dissociates
Not much
acid/base added,
but all of what’s
there dissociates
Weak
A lot of
acid/base
added, but little
dissociates
Not much
acid/base added
and very little
dissociates
Bases Strength & Concentration
Bases follow the same pattern as acids
A common misconception is acids are
dangerous but bases are not!
Vinegar is an acid we eat…some of them are
safe!
Sodium hydroxide is a very caustic base…not all
of them are less harmful than acids!
The stronger and acid or base is & the more
concentrated it is), the more dangerous it is for
you!
The Power of the Hydrogen: pH
The pH scale to measure the acidity of a
sample
Ways to measure pH
 Indicators change color based on pH
Liquid indicators – phenolphthalein or bromothymol blue
Bromothymol Blue: Acid: turns Yellow Base: turns blue
Phenolphthalein: Acid: stays clear Base: turns pink
Acid
Base
 pH meters or pH probes
Electronically determine pH and give a read-out
Ways to measure pH
 Indicators change color based on pH
Paper with a liquid indicator on it (pH paper or Litmus
paper)
pH paper turns a
color which matches
to a pH number
LITMUS PAPER (Mnemomic: See board!)
 Blue Litmus stays blue in a base
but turns pink in an acid
 Red Litmus stays red in an acid