Transcript Inorganic Nomenclaturex

Chemical Names and Formulas
• In chemistry, chemical names and formulas
are used interchangeably.
• You must learn how to shift back forth
between them, if given a name, write a
formula, and visa versa.
• We will start with the simplest inorganic
compounds, binary salts.
Inorganic Nomenclature
Naming Ionic Compounds
and Writing Formulas
Naming Binary Ionic Compounds
• Binary ionic compounds consist of a metal
cation and a non-metal anion.
• The metal always comes first.
• The –ide suffix is added to the end of the nonmetal.
Sodium chloride
Potassium sulfide
Magnesium oxide
Aluminum bromide
Given the formula, write the name
1)
MgS
2)
KBr
3)
Ba3N2
4)
Al2O3
5)
NaI
6)
SrF2
7)
Li2S
8)
RaCl2
9)
CaO
10) AlP
Given the name, write the formula
• Look up the common ionic charge for the
metal and non-metal on your reference table
This is shown as “Selected Oxidation States,” in the top
right hand corner of each element.
Note that non-metals often have more than one oxidation
state: ignore all but the top one for now.
Magnesium Oxide formula
• Look up oxidation states of Mg and O
Write each as an cation and anion
Mg2+ O2Criss cross the charges, making them
subscripts
Mg2O2
Reduce by dividing by common
denominator, if necessary
MgO
Oxidation numbers without lookups
Names  Formulas
2)
lithium bromide
3)
calcium nitride
4)
aluminum sulfide
5)
potassium iodide
6)
strontium chloride
7)
sodium sulfide
8)
radium bromide
9)
magnesium sulfide
10)
aluminum nitride
11)
cesium sulfide
12)
potassium chloride
13)
strontium phosphide
Polyvalent Metals
• Many of the d-block metals (transition metals)
are polyvalent: they have more than one type
of ion.
• For example, iron: Fe2+ and Fe3+
• There are two compounds of iron and oxygen:
FeO and Fe2O3
• Roman numerals are used to indicate the
charge on the cation – they become iron (II)
oxide and iron (III) oxide, respectively.
Common Polyvalent Metals
Fe
Cu
Sn
Au
Hg
Pb
Cr
Mn
Co
Rules for converting names to formulas
• Write ionic charges for polyvalent metal next
to the symbol, look up oxidation number for
the non-metal (always the negative one!)
• Criss-cross the charges to become subscripts;
reduce to lowest common denominator (if
necessary).
Formulas –> Names
1)
iron(II) chloride
2)
copper(I) sulfide
3)
lead(IV) iodide
4)
tin(II) fluoride
5)
mercury(I) bromide
6)
tin(II) oxide
7)
chromium(III) oxide
8)
gold(I) iodide
9)
manganese(II) nitride
10)
cobalt(III) phosphide
11)
iron(III) chloride
12)
copper(II) sulfide
13)
lead(II) bromide
Rules for converting formulas to names
• Look up oxidation number of non-metal
(always the negative one!)
• Count number of negative charges, divide by
subscript of the metal
• Write I, II, III, etc. after the metal name,
followed by the anion.
Formulas  Names
1)
CuS
2)
PbBr4
3)
Pb3N2
4)
Fe2O3
5)
FeI2
6)
Sn3P4
7) Cu2S
8) SnCl2
9) HgO
10)Hg2F2
11)CuCl2
12)CuBr
13)PbO
Polyatomic Ions
• Many ions are actually made of two or more
non-metals.
• Polyatomic ions have suffixes such as –ite, and
–ate that you have heard throughout your
lives.
• Reference Table E lists the more common
polyatomic ions.
Ternary Ionic Compounds
• Compounds containing polyatomic ions
commonly have three or more different
elements
• These are called ternary ionic compounds.
• You will need to learn to recognize polyatomic
ions in names and formulas, and go to your
reference tables to make conversions
• Memorizing polyatomic names, formulas and
charges is a good idea for future science
majors
Names  Formulas
1) silver carbonate
2) potassium hydrogen phosphate
3) aluminum hydroxide
4) sodium hydrogen carbonate
5) calcium acetate
6) potassium permanaganate
7) calcium perchlorate
8) lithium carbonate
Names  Formulas
9) magnesium hydrogen sulfite
10) sodium hypochlorite
11) tin(IV) chlorite
12) mercury(II) phosphate
13) tin(II) carbonate
14) mercury (I) acetate
15) lead(II) chromate
16) copper(I) sulfite
17) Tin (II) dichromate
Formulas  Names
1)
AlPO4
2)
KNO2
3)
NaHCO3
4)
CaCO3
5)
Mg(OH)2
6)
Na2CrO4
7)
Ba(CN)2
8)
K2SO4
9)
NaH2PO4
10)
NH4NO3
11)
Sn(NO3)2
12)
FePO4
13)
Cu2SO4
14)
Ni(C2H3O2)2
15)
HgCO3
All Types Together!!
NaMnO4
PbSO4
AlBr3
NH4NO3
FePO4
Al2(SO4)3
KCN
KHCO3
Hg(OH)2
Sn(HCO3)4
NaH
Fe(ClO4)3
Cu2CrO4
Iron (II) hydrogen sulfite
Aluminum perchlorate
Calcium chlorate
Ammonium hydroxide
Cobalt (II) iodide
Iron (III) carbonate
Iron (II) oxide
Silver sulfide
Potassium nitrate
Potassium nitrite
Ammonium chromate
Lead (IV) chlorite
Silver oxide
Iron (III) hydrogen carbonate
Barium hypochlorite
Copper (I) carbonate
Chemical Name
Metals are always stated first, by using the name of the element.
Non-metals are stated second. They always end with an –ide suffix
(sodium choride)
Metals with more than one valence are called polyvalent metals. The
charge on the ion (always positive) can be found on the periodic table in
the upper right corner of each element (oxidation numbers)
Polyvalent metals are given Roman numerals to distinguish them from
each other. (ex: Iron (II) and Iron (III))
Chemical Formula
Metals first, non-metals second. Subscripts indicate the number of atoms
of each element in the compounds.
Parenthesis (often used for polyatomic ions) indicate that everything
inside must be multiplied by the subscript.
Ex: Ca(NO3)2 has 2 atoms of N and 6 of O.
Polyvalent metals must be recognized! The common ones are Fe, Co,
Au, Pb, Sn, Cu, Mn, Cr, and Hg. The charge on the metal can be
determined from the non-metal or polyatomic ion.
Count the total number of negative charges (the charge on the ion *
subscript on the ion) and divide by the number of atoms of the cation to
get the charge on the cation.
Polyatomic ions are made up of combinations of non-metals, and
The charges on the polyatomic ions are found on Table E.
occasionally metals.
Polyatomic ions have unique names and charges. Many of them end in – Polyatomic ions always have the same charge.
ate or –ite suffixes. Most are negative ions. They can be found on Table E
(front page)
Chemical names often must be converted into formulas. Here is a simple
way to do this:
1.
Write the name of the metal, followed by the non-metal or
polyatomic ion.
2.
Write the charge of the negative ion as a superscript to the right of
the symbol. For non-metals, the charge is always the top oxidation
number on the periodic table. Polyatomic charges must be looked
up on Table E.
3.
Write the charge on the positive ion, given in the periodic table or
in the chemical name
4.
Criss-cross the ionic charges; the anion supersript becomes the
cation subscript; the cation charge becomes the number of anions.
5.
If necessary, reduce to lowest common denominator.
Ex. Barium Sulfate: Ba is +2; sulfate is SO42- from table E. Criss cross
leaves Ba2(SO4)2
Reduce to lowest common denomentator: BaSO4.
Examples:
CaCl2
1.
chloride has –1 charge. Calcium is always +2.
2.
Write name: calcium chloride (no II necessary)
Fe(NO3)3
1.
NO3 is nitrate (Table E), w/ -1 charge
2.
Fe can be II or III. Which one?
3.
Since there are 3 nitrates, the charge on the Fe must be +3
4.
Write the name: iron (III) nitrate.
(NH4)2CO3 : Both of these ions are on Table E! NH4+ is ammonium;
CO32- is carbonate; ammonium carbonate