Drill
Quiz
•
•
A molecule CH3Cl is a …. Molecule
Determine the shape of BF4.
Objective
• The student will be able to:
– Recognize and describe precipitates in
order to write the names and formulas
for the precipitates.
SAT/HSA Enrichment
•
a.
b.
c.
d.
Which of these substances moves
across cell membranes by osmosis?
Salt
Sugar
Water
Protein
Naming and Writing
Formulas
for Ionic Compounds
How do you name ionic compounds
and write their formulas?
Naming and Writing Formulas
for Ionic Compounds
• A recipe is a formula
for the sauce—a
complete list of
ingredients and their
proportions. Chemistry
also uses formulas.
Once you know the
rules, you can write the
formula for any
chemical compound.
Binary Ionic Compounds
• These masks are
made of an ionic
compound with
the common name
gypsum. This
name does not
tell you anything
about the
chemical
composition of
the compound,
though.
Binary Ionic Compounds
• Naming Binary Ionic Compounds
– A binary compound is composed of two
elements and can be either ionic or
molecular.
• To name any binary ionic compound, place
the cation name first, followed by the
anion name.
Binary Ionic Compounds
• Tin(II) sulfide,
or SnF2, is added
to toothpastes
to prevent
cavities.
Binary Ionic Compounds
• Tin(IV) sulfide,
or SnS2, is used
in glazes for
porcelain
fixtures and
dishes.
Binary Ionic Compounds
• Hematite, a
common ore
of iron,
contains iron
(III) oxide.
The
balanced
formula is
Fe2O3.
Binary Ionic Compounds
• Writing Formulas for Binary Ionic
Compounds
– Write the symbol of the cation and
then the anion. Add whatever
subscripts are needed to balance the
charges.
9.2
Conceptual Problem
9.2
Conceptual Problem
9.2
Conceptual Problem
Compounds With Polyatomic
Ions
• Write the symbol for the cation
followed by the formula for the
polyatomic ion and balance the
charges.
Compounds With Polyatomic
Ions
• For example, calcium nitrate is composed
of a calcium cation (Ca2+) and a polyatomic
nitrate anion (NO3–).
– In calcium nitrate, two nitrate anions, each
with a 1– charge, are needed to balance the
2+ charge of each calcium cation. The
formula for calcium nitrate is Ca(NO3)2.
Compounds With Polyatomic
Ions
• Oysters produce calcium carbonate
to form their shells and sometimes
pearls.
Compounds With Polyatomic
Ions
• Lead(II)sulfate is an important
component of an automobile battery.
9.3
Conceptual Problem
9.3
Conceptual Problem
9.3
Conceptual Problem
9.2
Compounds With Polyatomic
Ions
• Naming Compounds with Polyatomic
Ions
– To name a compound containing a
polyatomic ion, state the cation first
and then the anion, just as you did in
naming binary ionic compounds.
9.2
Compounds With Polyatomic
Ions
• Sodium hypochlorite
(NaClO) is used as a
disinfectant for
swimming pools. The
metallic cation in
this compound is
sodium (Na+) so the
polyatomic ion must
be ClO–.
Section Quiz
1.The correct name for CrCl3 is
a.
b.
c.
d.
chromium chlorine.
chromium(III) chloride.
monochromium trichloride.
chromium(III) trichloride.
Section Quiz
2.What is the correct formula for strontium
nitride?
a.
b.
c.
d.
Sr3N2
SrN2
Sr2N3
Sr3N
Section Quiz
3.Which one of the following compounds is
named correctly?
a.
b.
c.
d.
sodium chlorite, NaClO
potassium nitrate, KNO2
sodium acetate, NaC2H3O2
lithium sulfate, Li2SO3
Criss-Cross Method
• Writing Formulas Worksheet!
– Each student is responsible for 1 or 2
problems.
• Be ready to share!
Small-Scale Lab
• Chemical Names and Formulas
– Purpose:
• Write the chemical names and formulas of
common chemical compounds.
• Describe the colors and textures of common
ionic compounds.
• Synthesis chemical compounds, and write
their names and formulas.
Summary
1. Did we accomplish the objective? Explain.
2. How do ionic compounds form?
3. Describe how to determine the names of
binary ionic compounds.
4. Describe how to write the formula of
binary ionic compounds.
5. Compare and contrast naming binary and
polyatomic ionic compounds.
6. Design a way to remember how to
determine the name of ionic compounds.
Homework
• Writing Formulas (Criss-Cross
Method) worksheet
– Complete 5 rows