ionic compounds. ion formation octet rule- atoms want a full valence shell ▫_____ valence...
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Ionic Compounds
Ion formation•Octet rule- atoms want a full valence shell
▫ _____ valence electrons for most atoms▫ ____ and atoms that become isoelectronic with __ are
satisfied with ____ valence electrons▫ H can be satisfied with ___ or ___
•_____________▫ Low electronegativities and ionization energies ▫ Electrons are __________ until octet rule is satisfied (more
complicated in the transition metals)•______________
▫ High electronegativities and ionization energies ▫ Electrons are ________ until octet rule is satisfied
Valence electrons
Ions•An atom with a _____________
▫Imbalance of _________ and _________▫_____ or ______ electrons
•Two Types ▫Cation- __ charge because electrons are __
Cation with a common charge Multivalent cation Polyatomic cation
▫Anion- _ charge because electrons are ____ Anion with a common charge Polyatomic anion
Cations with a Common Charge
•Atoms that predictably form a cation with a certain charge
•Group 1 elements- form cations with __ charge
•Group 2 elements- form cations with ___ charge
•Al- forms cations with a ___ charge•Some of the other metals will also only
form one common ion
Multivalent Cations•Atoms that form multiple types of
cations
•All other metals not on the common cation list
Polyatomic Cations•Cation made up of multiple atoms
bonded together
•You only memorized one
NH4+
+
Naming Cations•Cations with a common charge
▫ “Element name” ion For example
Na+ is _____________ Ca+2 is _____________
•Multivalent cations▫ “Element name” (Roman numeral for charge) ion
For example Fe+2 is _____________ Fe+3 is _____________
•Polyatomic cations▫ “Polyatomic name” ion
NH4+ is _______________
Anions with a Common Charge
•Atoms that predictably form a anion with a certain charge
•Group 17 non-metals- form anions with __ charge•Group 16 non-metals- form anions with __ charge•Group 15 non-metals- forms anions with a ___
charge•Sometime Group 14 non-metals form anions with
a ____ charge
Polyatomic Anions
•Anion made up of multiple atoms bonded together
•You memorized 10, but by learning a set of rules you know more than 10.
•For polyatomics with oxygen ending with –ate▫Add one more oxygen, name is _________▫Take away one oxygen, name is ________▫Take away two oxygens, name is ________
CO32
-
2-
Polyatomic Anions (cont)• For example:
▫ You memorized ClO3- is chlorate
This ion has one chlorine and three oxygen atoms with a negative one charge
▫ ClO4- is _____________
This ion has one chlorine and four oxygen atoms (one more than the –ate ion) with a negative one charge
▫ ClO2- is ____________
This ion has one chlorine and two oxygen atoms (one less than the –ate ion) with a negative one charge
▫ ClO- is _____________ This ion has one chlorine and one oxygen atom (two less than
the –ate ion) with a negative one charge
Naming Anions•Anions with a common charge
▫ “Element name with ending changed to -ide” ion For example
Cl- is ____________ O-2 is ____________
•Polyatomic anions▫ “Polyatomic name” ion
For example CO3
-2 is ___________ NO3
- is ___________ NO2
- is ___________
Ionic bonding•Ions of opposite charges are attracted to each other
•This attraction is a chemical bond
F
Na
Electron is transferred
Na F
Charges
Na F+1 -1
Atoms are attracted to each other
Na F+1 -1
And each have 8 valence electrons
Bonds
•Chemical bonds are _______________
•They act between atoms within a molecule
Why does bonding occur?
•Bonding occurs to maximize stability of the atoms involved.
•More stable = LOWER potential energy
Ionic Compounds
•Will often form a crystal structure
•Can be identified by name or formula▫ If given one, you can find the
other▫ Formulas give the smallest
whole number ratio between the ions
Naming Ionic Compounds
•Determine the name of the cation and anion involved in the ionic bond
•Name both (cation before anion) leaving off the “ion”▫ For example
An ionic compound between a magnesium ion and a fluoride ion would be ________________
An ionic compound between a copper (I) ion and a phosphate ion would be _________________
Formulas•Elements in the compound are listed
with the number of atoms of each type listed as subscripts▫For example, NaCl
Has a 1:1 ratio of sodium ions to chloride ions
▫CaI2
Has a 1:2 ratio of calcium ions to iodide ions
Formulas (cont.)
•Formulas with polyatomic ions can have parenthesis with a subscript on the outside
•The subscript on the outside denotes how many polyatomic ions are there ▫For example, Al(NO3)3
Has a 1:3 ratio of aluminum ions to nitrate ions
Switching Between Names and Formulas
•Name to Formula▫ Identify the symbol and charge of the anion
and the cation▫ Determine how many of cations and anions
are needed to balance the charges to neutral▫ Write the formula (cation first) with
subscripts denoting how many are needed of each ion Remember to put polyatomic ions in
parenthesis if adding a subscript to them
Switching Between Names and FormulasName to Formula example
▫What is the formula for calcium bromide?
Switching Between Names and FormulasName to Formula example
▫What is the formula for iron (II) chloride?
Switching Between Names and FormulasName to Formula example
▫What is the formula for potassium hydroxide?
Switching Between Names and Formulas•Name to Formula example
▫What is the formula for gold (II) phosphate?
Switching Between Names and Formulas•Name to Formula example
▫What is the formula for ammonium bromide?
Switching Between Names and Formulas
•Formula to name▫ Identify the name of the cation and anion in
the formula Remember multivalent cations need a Roman
numeral as part of their name. You will have to determine the charge from the formula clues.
▫ Name the compound
Switching Between Names and Formulas
•Formula to name examples▫ LiBr
▫ NiO