SDSU
Ion Naming Test
Chem 201
Common Ions
The following are the names, formulas and charges of the common ions that you need to
know. There will be an exam on these in your lab on the date indicated in the schedule. You
need to get at least 80% correct in order to pass Chem 201. If you pass the exam on the first try
you will be rewarded with 5 extra credit points. If you do not get 80% correct you will be given a
second opportunity to take the test in lab. The second test will be similar but not the same as the
first. If you do not get 80% correct on the second try, you will need to meet with me. YOU
MUST PASS THIS TEST BEFORE EXAM 1.
Note that I will keep on asking naming questions on exams and quizzes, so you will be
awarded with easy points once you’ve learned these!!
Cations
lithium
sodium
potassium
silver
magnesium
calcium
barium
zinc
Li+
Na+
K+
Ag+
Mg2+
Ca2+
Ba2+
Zn2+
aluminum
chromium(III)
cobalt(II)
copper(I)
copper(II)
iron(II)
iron(III)
lead(II)
Al3+
Cr3+
Co2+
Cu+
Cu2+
Fe2+
Fe3+
Pb2+
manganese(II)
mercury(I)
mercury(II)
nickel(II)
tin(II)
ammonium
hydronium
Mn2+
Hg22+
Hg2+
Ni2+
Sn2+
NH4+
H3O+
Note that roman numerals are used to indicate the charge when an ion commonly exists in more
than one oxidation state (charge). Because Group I ions always have a +1 charge and Group II
ions always have a +2 charge, roman numerals are not used with these. They are however used
with the majority of the other monatomic cations. The exceptions in the above list are Al, Zn and
Ag, which conveniently fall in a diagonal line in the periodic table.
Anions
fluoride
chloride
bromide
iodide
oxide
sulfide
hydroxide
F!
Cl!
Br!
I!
O2!
S2!
OH!
cyanide
thiocyanate
acetate
chlorate
perchlorate
nitrate
permanganate
CN!
SCN!
CH3CO2!
ClO3!
ClO4!
NO3!
MnO4!
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carbonate
hydrogen carbonate
oxalate
dichromate
chromate
sulfate
phosphate
CO32!
HCO3!
C2O42!
Cr2O72!
CrO42!
SO42!
PO43!
SDSU
Ion Naming Test
Chem 201
Naming Rules
The cation is named first, then the anion. No prefixes are used to indicate the number of each,
since if you know the ion charges you can determine how many of each will be in the chemical
formula. The overall charge has to be zero, so each ion in the formula is multiplied by the
smallest integer that will give an overall charge of zero.
Example:
aluminum chloride
aluminum = Al3+
chloride = Cl!
Since chloride is !1, three chlorides are needed to cancel the +3 of aluminum.
The formula is AlCl3.
Example:
iron(III) sulfate
iron(III) = Fe3+
sulfate = SO42!
Since iron(III) is +3 and sulfate is !2, both ions have to be multiplied by integers
in order to cancel the charges. The smallest integers would be 2 for iron(III) (to
give a total +6) and 3 for sulfate (to give a total !6).
The formula is Fe2(SO4)3.
Note that parentheses are placed around a polyatomic ion when more than one is
used.
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SDSU
Ion Naming Test
Chem 201
Practice Exam
Name the following ionic compounds:
1.
BaBr2
2.
NaNO3
3.
NH4 [CH3 CO2 ]
4.
CuSO4
5.
Fe2 O3
6.
ZnCl2
7.
Na2 Cr2 O7
8.
Cr(OH)3
9.
KClO3
10.
LiHCO3
Give the correct molecular formula for the following:
1.
sodium perchlorate
2.
calcium phosphate
3.
copper(I) nitrate
4.
mercury(II) iodide
5.
potassium permanganate
6.
zinc sulfide
7.
lead(II) sulfate
8.
lithium dichromate
9.
manganese(II) fluoride
10.
barium acetate
answers: barium bromide, sodium nitrate, ammonium acetate, copper(II) sulfate, iron(III) oxide, zinc chloride,
sodium dichromate, chromium(III) hyd roxid e, potassium chlora te, lithium hyd rogen carb onate, NaClO 4, Ca3(PO 4) 2,
CuNO3, HgI 2, KM nO 4, ZnS, PbSO 4, Li2Cr 2O 7, MnF 2, Ba(CH 3CO 2) 2.
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