Name:
Date:
Block:
CHAPTER 4.2 (PART 2 OF 3): IONIC COMPOUNDS WITH
MULTIVALENT IONS AND POLYATOMIC IONS
BACKGROUND:
Recall that:
1. name of ionic compound  metal + non-metal + “-ide” ending
2. criss-cross method to make formulae of ionic compounds
3. some metals are _______________  they can lose different amounts of electrons depending on
the situation
 multivalent metals have 2 or more ___________________
e.g. Nickel (Ni) is a multivalent metal and has ion charges of 2+ and 3+ (Ni 2+ or Ni3+)
Ni2+ is called “nickel 2” or nickel (II) and Ni3+ is called “nickel 3” or nickel (III)
HOW TO WRITE THE
NAME OF IONIC COMPOUNDS WITH MULTIVALENT METALS
1. The name depends on the ion charge of the multivalent metal (which charge are you using?)
2. reverse criss-cross  the subscript on the non-metal becomes the ion charge of the metal
Example #1: NiCl2
Example #2: NiCl3
Roman Numerals:
1
2
3
4
5
6
7
* Double check the POSSIBLE ion charges of a multivalent metal from the Periodic Table of Elements.
Some charges may be reduced in the final name or formula of a compound.
e.g. Chromium can only be chromium(II) or chromium(III)
Mr. Lau
Chemistry
Science 10
Name:
Date:
Block:
Write the name of the following ionic compounds that have multivalent metals:
A. Cu2O
____________________________
B. CuO
____________________________
C. CrF2
____________________________
D. CrF3
____________________________
E. VCl5
____________________________
F. Mo2O3
____________________________
HOW TO WRITE THE
FORMULA
G. Mn2S3
____________________________
H. Cr3S2
____________________________
I. TiO2
____________________________
J. PbS2
____________________________
K. FeS
____________________________
L. Fe2S3
____________________________
OF IONIC COMPOUNDS WITH
MULTIVALENT METALS
1. Identify the ion charge of the metal ion  what Roman numeral does it have?
2. Use the regular criss-cross method to determine the formula
Example #3:
What is the formula for copper(I) nitride?
Example #4:
What is the formula for iron(II) phosphide?
Write the formula of the following ionic compounds:
A. manganese(II) oxide
C. chromium(II) bromide
_________________________________
B. manganese(IV) oxide
D. chromium(III) bromide
_________________________________
Mr. Lau
_________________________________
Chemistry
_________________________________
Science 10
Name:
Date:
E. lead(IV) chloride
H. copper(I) iodide
_________________________________
F. mercury(II) fluoride
G. iron(III) phosphide

_________________________________
J. copper(II) selenide
_________________________________
FORMULA
_________________________________
I. copper(II) iodide
_________________________________
HOW TO WRITE THE
Block:
_________________________________
FOR IONIC COMPOUNDS WITH
POLYATOMIC IONS
an ion composed of more than one type of atom joined by a covalent bond
o Poly = many  polyatomic ion = ion with many atoms
e.g. CO32- is the polyatomic ion called ___________________

the polyatomic ion ___________________________ like a simple ion with an ion charge
o you must be able to identify a polyatomic ion and treat it like any other simple ions
o except for ammonium which acts like a metal ion, treat polyatomic ions like a non-metal ion
Example #5: Write the formula for potassium
permanganate.
Example #6: Write the formula for aluminum
hydroxide
*notice that brackets are used to properly show the ration of anion to cation
Mr. Lau
Chemistry
Science 10
Name:
Date:
Block:
Write the formula of the following ionic compounds:
A. ammonium nitrate
D. vanadium(V) nitrate
_________________________________
B. sodium chromate
_________________________________
E. magnesium acetate
_________________________________
C. lead(II) perchlorate
_________________________________
F. tin(II) cyanide
_________________________________
HOW TO WRITE THE
_________________________________
NAME OF IONIC COMPOUNDS WITH POLYATOMIC IONS
The hardest part is ‘seeing’ the polyatomic ion. Other than that, naming is straight forward.
Write the names of the following compounds with polyatomic ions:
A. KCH3COO
_________________________________
B. Ca(CH3COO)
_________________________________
C. (NH4)3P
_________________________________
D. (NH4)3PO4
_________________________________
E. Fe(OH)3
_________________________________
F. K2CrO4
_________________________________
G. K2Cr2O7
_________________________________
H. Ca(HCO3)2
_________________________________
Mr. Lau
Chemistry
Science 10