C
Complicated
li
d Ionic
I i
The formulas of complicated ionic compounds are derived from
their names the same way simple ionic compounds are, by
making
ki the
h net positive
i i charge
h
off the
h cations
i
equall the
h net
negative charge on the anions. The charges of the cations are
actually easier because they are given in the name with Roman
numerals. The only difficulty then, is remembering the charges
of the complex
p ions.
C
Complicated
li
d Ionic
I i
Example 1. Iron(II) chloride
Cation Atom: Fe 2+ Charge: +2
Anion Atom: Cl- Charge: -1
1st try
Formula FeCl, Net charge [1(+2) +1(-1)] = +1
Wrong, try again increase the negative ion
2ndd try
Formula FeCl2, Net charge[1(+2) +2(-1)] = 0
No net charge Correct
C
Complicated
li
d Ionic
I i
Example 2. Iron(II) nitrate
Cation Atom: Fe2+
Charge: +2
A i
Anion
C
Complex:
l NO3Ch
Charge:
-11
1st try
Formula: FeNO3, Net charge [1(+2) +1(-1)] = +1
Wrong, try again increase the negative ion
2nd try
Formula: Fe(NO3)2, Net charge [1(+2) +2(-1)] = 0
No net charge Correct
C
Complicated
li
d Ionic
I i
Example 3. Ammonium nitrate
Cation Complex NH4+ Charge: +1
Anion Complex: NO3Charge: -1
1st try
Formula: NH4NO3, Net charge [1(+1) +1(-1)] = 0
No net charge Correct
C
Complicated
li
d Ionic
I i
Problems to try
Copper(IV) fluoride
L d(II) nitrite
Lead(II)
i i
Chromium (VI) hydroxide
Iron(III) sulfate
Molybdenum(IV) oxide
Ammonium phosphate
p p
C
Complicated
li
d Ionic
I i
Problems to try
Copper(IV) fluoride
L d(II) nitrite
Lead(II)
i i
Chromium(VI) hydroxide
Iron(III) sulfate
Molybdenum(IV) oxide
Ammonium pphosphate
p
CuF4
Pb(NO2)2
Cr(OH)6
Fe2(SO4)3
MoO2
((NH4)3PO4
1(+4) + 4(-1)
1( 2) +2(-1)
1(+2)
2( 1)
1(+6) +6(-1)
2(+3) +3(
+3(-2)
2)
1(+4) - 2(-2)
3(+1)
( ) + 1(-3)
( )