SNC 2D
Unit: Chemical Reactions
Ionic Compounds: Names, Formulas and Properties
A.
Name: _______________________
Date: _______________________
Ions

Cations are atoms that have lost one or more electrons to become positively charged (in an effort to end up with a full valence shell); metals form cations.
Cation names are the same as the name of the atom. [e.g. The lithium atom forms the lithium ion.]

Anions are atoms that have gained one or more electrons to become negatively charged (in an effort to end up with a full valence shell); non-metals form
Practice
anions. Anion names end in “-ide”. [e.g. The fluorine atom forms the fluoride ion.]
Fill in the following table, then, complete the “Summary” on the next page by choosing the correct words in brackets or filling in the blanks.
Group number
Electron Dot Diagram for
a Sample Atom
Ion Symbol
1 - metal
Ion Name
Cation or
anion?
What happened to
form the ion?
Lithium ion
Cation
One valence electron
was lost from the Li
atom.
OR
2 - metal
13 – metal (mostly metals)
14 – non-metal
No ions formed.
15 – non-metal
Nitride ion
16 – non-metal
17 – non-metal
18 – non-metal (noble gases)
No ions formed.
Some Special Metallic Ions – Multivalent Metals
Many metals in the periodic table have more than one possible ion they can form. These metals are called multivalent. (Those that form only one kind
of ion are called monovalent.) Different ions formed from the same multivalent metal are given different names by adding a Roman numeral in
brackets after the name of the metal to show which ion has formed. Use your periodic table to help fill in the example for mercury below.
Multivalent Metal
Ions Formed
Multivalent Metal
Ions Formed
Multivalent Metal
Copper
Cu1+ copper(I)
Lead
Pb2+ lead(II)
mercury
Cu2+ copper(II)
Pb4+ lead(IV)
Ions Formed
Summary

An ion is an atom that has (the same number of protons and electrons; lost or gained at least one valence electron).

In general, when forming ions, metals tend to (lose, gain) valence electrons to form (positively charged, negatively charged) ions called
(anions, cations). In general, when forming ions, non-metals tend to (lose, gain) valence electrons to form (positively charged, negatively charged)
ions called (anions, cations).

Atoms in group numbers ___ and ___ do not normally form ions.

Ions of metals are named (just like the atom they came from; with an –ide ending). Ions of non-metals are named (just like the atom they came
from; with an –ide ending).

Some metals in the periodic table can form an ion with only one possible charge. These metals are called (monovalent, multivalent). Many metals in
the periodic table can form ions with more than one possible charge. These metals are called (monovalent, multivalent). The names of these
multivalent metallic ions contain a Roman numeral in brackets to indicate (the atomic number, the charge on the ion).

Here are some common Roman numerals you should be able to recognize: I = ___ II = ___ III = ____ IV = ____ V = ___ VI = __ VII = __
B. Ionic Compounds and Ionic Bonds

Ionic compounds contain ions that are attracted together by their opposite charges. This attraction is called an ionic bond.

The “net” or overall charge on any ionic compound is zero because it contains the same number of cations (+) as anions (-).
C. Binary Ionic Compounds

contain two different types of elements; one of the elements is a metal and the other one is a non-metal

both of the elements have formed ions to make the ionic compound
Practice
1.
Use your periodic table to help decide whether each of the following substances is a “molecule” or “a binary ionic compound”. If it is a binary
compound, write out the ions present…..
a)
HCl
b)
NaF
f)
H2O
___________________________________
___________________________________
___________________________________
d) O2 (g) __________________________________________
e) LiCl
g) N2O4
__________________________________________
_________________________________________
D. (continued) Binary Ionic Compounds
1. Naming Binary Ionic Compounds from a Formula
Steps:
I. The metal always comes first. Check to see whether it is monovalent or multivalent. If it is monovalent, just name it. If it is multivalent,
name it with its Roman numeral in brackets to indicate the charge on the ion in the compound. Unsure of the charge? Figure out the charge
on the non-metal ion. The metal ion must give an equal, opposite charge so that the overall charge together is zero.
II. Name the non-metallic ion. Remember that these ions end in “-ide”.
Examples and Practice:
Formula
Name
Formula
Name
Formula
Name
Practice to Do
NaCl
Sodium chloride
MgF2
Magnesium fluoride
CuO
Copper(II) oxide
(oxygen is O2- so the Cu must be
the Cu2+ rather than the Cu1+ )
a) LiBr
b) CaI2 c) Al2O3
d) Mg3N2 e) FeCl2 f) FeCl3
g) Cu3N2 h) Ni2O3
2. Two Methods for Writing Formulas for Binary Ionic Compounds from a Name
Method A: Complete the table below to practice using this reasoning method.
Examples
Calcium bromide
Magnesium nitride
Copper(II) oxide
Steps
1. Examine the name of the compound and
use the periodic table to identify the
ions and their charges.
2. Determine the number of each ion
needed to balance the positive and
negative charges so that the overall
charge will be zero.
3. Note the ratio of positive to negative
ions. These values will be the
subscripts in the formula in step 4.
4. Write the chemical formula, using
subscripts (from the ratios in step
#3) to show how many of each atom
is needed. If the subscript is “1”, do
not write it in.
1 Ca2+ ions to 2 Br1- ions
3 Mg2+ ions to 2 N3- ions
1 Cu2+ ion to 1 O2- ion
Method B: “Crossover Method” for Writing Formulas for Binary Ionic Compounds
Determining the formula for…
a)
magnesium chloride
Ions with charges from the periodic table:
Crossover the numerical value of each
Mg2+
Do not write the subscript, 1, in the
final answer.
c)
calcium bromide
d)
magnesium nitride
e)
copper(II) oxide
Cl1-
Mg2+
Cl1-
charge to be a subscript for the other
ion. [Ignore the signs.]
b)
Examples
MgCl2
calcium oxide
Ca2+
O2-
Crossing over result
Ca2
O2
Express the final ratios
in simplest terms. Do not
show the subscript, 1.
CaO
Practice – DO THIS FIRST, PLEASE: Put the title “Binary Ionic Compounds – Practice” on the top of a piece of looseleaf. Make a table on the paper with
the following headings “Name” and “Formula”. Put all of the substances in questions 1 and 2 into your table so that when you have finished doing the work,
you have one complete table. Leave AT LEAST one open line between each substance so you have working room.
1. Give the name for each of the following formulas.
2. Work out the correct formula for each of the following names.
Formula
Name
a) ZnO
i) Beryllium oxide
b) Na2O
j) Rubidium bromide
c)) Mg3N2
k) Iron(II) oxide
d) CuO
l) Copper(I) chloride
e) Cu2O
m) Chromium(III) sulphide
f) PbO2
n) Calcium fluoride
g) Fe2O3
o) Potassium oxide
h) Ba3P2
p) Manganese(IV) nitride