Chem Chapter 7 Chemical Formulas & Nomenclature
Positive Ion (Cation) Formation
metals tend to lose valence electrons to become stable and form positive ions called cations
Mercury (I) ion (Mercurous ion)
*Hg2 2+
only charge on Ag
1+
only charge on Zn
2+
typical charge on group 2A metals
2+
only charge on Al
3+
Mg₃N₂
Magnesium Nitride
Ionic Compound Formation
Total number of electrons transferred by the metal must equal the total number of electrons accepted by the nonmetal.
what is an ion
an atom that has either gained/lost electrons
Monatomic ion
an ion formed by only one atom
typical charge on group 1 metals
1+
Binary Ionic Compound Formulas
1. Metal written first Nonmetal written second 2. Use criss-cross method and subscripts to insure sum of charges = 0
Bi(HSO₄)₃
Bismuth(III) Bisulfate
Cd(NO₃)₂
Cadmium Nitrate
CsCN
Cesium Cyanide
CuBr
Copper(I) Bromide
CuSO₄
Copper(II) Sulfate
Chromium (II) ion (Chromous ion)
Cr2+
Chromium (III) ion (Chromic ion)
Cr3+
Copper (I) ion (Cuprous ion)
Cu+
Copper (II) ion (Cupric ion)
Cu2+
Oxidation number
the positive or negative charge of a monatomic ion
Formula unit
the simplest ratio of ions represented in an ionic compound
AlH₃
Aluminium Hydride
AlP
Aluminium Phosphide
Al₂(CO₃)₃
Aluminum Carbonate
(NH₄)PO₄
Ammonium Phosphate
(NH₄)₂S
Ammonium Sulfide
AsCl₃
Arsenic Trichloride
write the empirical formula for Ba²⁺ + Cl⁻
BaCl₂
Ba(ClO)₂
Barium Hypochlorite
Cr(NO₃)₃
Chromium(III) Nitrate
Cobalt (II) ion (Cobaltous ion)
Co2+
Cobalt (III) ion (Cobaltic ion)
Co3+
Co(ClO₃)₂
Cobalt(I) Chlorate
CoCl₂
Cobalt(II) Chloride
Co(HSO₃)₄
Cobalt(IV) Bisulfite
Iron (II) ion (Ferrous ion)
Fe2+
Iron (III) ion (Ferric ion)
Fe3+
Do Transition Metals for Cations or Anions?
Form positive ions (cations), but not always with the same charge.
Mercury (II) ion (Mercuric ion)
Hg2+
H₂O₂
Hydrogen Peroxide
Oxidation Number =
Ion Charge - number of electrons transferred to or away from an atom when it becomes an ion.
Fe₂O₃
Iron (III) Oxide
FeCrO₄
Iron(II) Cromate
Pb(HCO₃)₂
Lead(II) Bicarbonate
PbO₂
Lead(II) Peroxide
LiOH
Lithium Hydroxide
Mg(HSO₃)₂
Magnesium Bisulfite
Mg(ClO₂)₂
Magnesium Chlorite
HgCL₂
Mercury(II) Chloride
Criss-Cross Method
Method used to insure that there is a balance between the number of electrons transferred by the metal to the nonmetal.
Manganese (II) ion (Manganous ion)
Mn2+
Manganese (III) ion (Manganic ion)
Mn3+
write the formula for Na⁺ + Cl⁻
NaCl
Ni(ClO₃)₂
Nickel(II) Chlorate
NiSO₃
Nickel(II) Sulfite
Nonmetal Anion Names end in __________
Nitride (N³⁻), Phosphide (P³⁻), Oxide (O²⁻), Sulfide (S²⁻),Fluoride (F¹⁻), Chloride (Cl¹⁻), , Bromide (Br¹⁻), , Iodide (I¹⁻)
Negative Ion (anion) Formation
Nonmetals tend to gain valence electrons to become stable and form negative ions called anions.
In order to become stable, atoms will either gain or lose valence electrons in order to acquire an _________. (like a Noble Gas)
Octet.
Lead (II) ion (Plumbous ion)
Pb2+
Lead (IV) ion (Plumbic ion)
Pb4+
Pt(CN)₄
Platinum(IV) Cyanide
Common Polyatomic Ions
Polyatomic ions have their own names and charges and must either be memorized or looked up on a chart
KClO₃
Potassium Chlorate
Rb₂CrO₄
Rubidium Chromate
AgI
Silver Iodide
Tin (II) ion (Stannous ion)
Sn2+
Tin (IV) ion (Stannic ion)
Sn4+
Na₂Cr₂O₇
Sodium Dichromate
Na₂SO₄
Sodium Sulfate
Sr₃(PO₄)₂
Strontium Phosphate
SrS
Strontium Sulfide
SnF₄
Tin (IV) Fluoride
Sn₃(PO₄)₂
Tin Phosphate
SnBr₂
Tin(II) Brimide
The reactivity of an atom is related to its _________ electrons
Valence
ZnCr₂O₇
Zinc Chromate
ZnNO₂
Zinc Nitrite
crystal lattice
a 3-dimensional geometrical structure formed by the alternative arrangement of positive and negative ions Shown above: crystal lattice of NaCl.
Oxyanion
a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms
Polyatomic ions
an ion made up of two or more atoms bonded together that acts as a single unit with a net charge
Anion
an ion with a negative charge
Cation
an ion with a positive charge
Electrolyte
an ionic compound whose aqueous solution conducts an electric current
name of ions with - charges
anions "a nEGATIVE ion"
ions
atoms that have acquired either a positive or a negative charge.
Formation of an Ionic Bond
between a metal that loses one or more valence electrons and a nonmetal that gains one or more valence electrons.
name of ions with + charges
cations "c a + ion"
Formula Unit
chemical formula for an ionic compound; simplest ratio of positive to negative ions; overall charge = 0
Polyatomic Ions
ions made up of more than one atom; acts as an individual ion in a compound; charge applies to entire group of atoms.
Stock system
it is a widely used system of chemical nomenclature developed by the german chemist Alfred Stock. In this system, the oxidation states of some or all the elements in a compound are indicated in parentheses by Roman numerals
Differentiate between molecular and ionic compounds
metal + non-metal = ionic compound non-metal + non-metal = molecular compound
Monatomic Ions
one-atom ions
Properties of Ionic Compounds
strong attraction between oppositely charged ions means: high melting & boiling points ionic crystals are very hard but brittle conduct electricity when dissolved in solution or melted (ELECTROLYTES)
If the metal loses more electrons than the nonmetal gains,then __________ must be used to balance the charges
subscripts.
Ionic bond
the electrostatic force that holds oppositely charged particles together in an ionic compound
Lattice energy
the energy required to separate one mole of the ions of an ionic compound, which is directly related to the size of the ions bonded and is also affected by the charge of the ions
Chemical bond
the force that holds two atoms together; may form by the attraction of a positive ion for a negative ion or by sharing electrons
Alloy
the mixture of elements that has metallic properties; most commonly forms when the elements are either similar in size, or the atoms of one element are much smaller than the atoms of the other
