Ionic Compounds

Bonds Chemical bonds are __________ forces 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

Bond types Dependent on the difference between the __________________ of the elements involved in bond ▫Electronegativity  Ability of an atom to ________________  Highest found in _______________  _________ are not ranked

Bond Types (cont) To Determine Type ▫Subtract the electronegativities ▫If difference is  ______ – bond is non-polar covalent  ______- bond is polar covalent  Greater than ______

Bonding is all about the electrons! Bond type tells us what will happen to the electron(s) Octet rule will give us an idea of how many electrons will be involved ▫Have to look at __________________ ▫Remember most atoms are stable with ___ ▫Common exceptions  H, He, Li, and Be can be stable with 2  B is stable with 6  Elements with d orbitals (can have more than 8)

Valence electrons

Ionic bonding Ionic bonding involves the ______ of valence electrons. Creates _____ ▫Cation- + ion (___ electrons) ▫Anion- - ion (____ electrons) Ions of opposite charges are attracted to each other (the attraction is the bond)

Na

F

Electron is transferred Na F

Charges Na F +1

Atoms are attracted to each other Na F +1 And each have 8 valence electrons

Ionic Compounds Will often form a _____ structure Formulas give the ___________ number ratio between the ions

Formulas Elements in the compound are listed with the number of atoms of each type listed as ___________ ▫For example, NaCl  Has a ___ ratio of Na + ions and Cl - ions ▫CaI 2  Has a ___ ratio of Ca +2 ions to I - ions

Formulas (cont.) More complex formulas can have parenthesis with a subscript on the outside The subscript on the outside applies to all elements ___ the parenthesis ▫For example, Al(NO 3 ) 3  Has __ Al atom  ___ N Atoms  And ___ O atoms

Binary Compounds Compounds only containing ___________ of elements ▫For example  H 2 0  FeI 3  NaCl  Ag 2 S  CaBr 2

Ionic Compounds: Binary Binary: Metal bonded with Nonmetal ▫Type 1- Metal comes from Group ___________ ▫Type 2- Metal comes from Group _________  Transition metals are multivalent (can take multiple charges)  Except Ag (___), Cd (___), and Zn (___)- treat these like type 1

Base Name _______ is named Anion is named, but ending is changed to _____

Binary Compounds: Type 1 Compound made from a metal from group 1, 2, Al, Ag, Cd, or Zn with a nonmetal (ionic bond) ▫For example: NaCl, BeF 2, Al 2 O 3, K 2 S Metal forms a cation ▫Group 1- ___ ▫Group 2- ___ ▫Al- ___ ▫Ag- ___ ▫Cd- ___ ▫Zn- ___ Nonmetal forms an anion ▫Sometimes Group 14- ____ ▫Group 15- ____ ▫Group 16-____ ▫Group 17- ____

Creating Type 1 Formulas Steps 1.Determine the charge of the ion that each element will form 2.Determine how many ions of each type will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s symbol 3.Make sure the formula is reduced to its simplest form

Creating Type 1 Formulas (cont) For example, ▫What is the formula for a compound made of calcium and bromine? Ca 2+ Br-

Naming Type 1 Compounds Base Name ________ ▫Metal is named first ▫Make sure to change the ending of the anion to -ide ▫For example:  NaCl is ___________  CaBr 2 is ____________  Li 2 O is _____________

Binary Compounds: Type 2 Compound made from a metal from group 3-12 (transition metals or multivalent metals) with a nonmetal (ionic bond) ▫For example: FeCl 2, FeCl 3, Cu 2 S 3 Metal forms a cation ▫Charges vary from element to element ▫Most of the transition elements can have several different charges Nonmetal forms an anion ▫Sometimes Group ▫Group ▫Group ▫Group

Creating Type 2 Formulas 1.Determine the charge of the anion (the charge of metal will be given to you) 2.Determine how many ions of each type will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s symbol 3.Make sure the formula is reduced to its simplest form

Creating Type 2 Formulas (cont) For example, ▫What is the formula for a compound made of iron (+2) and chlorine? Fe 2+ Cl-

Naming Type 2 Compounds Base Name + Roman numeral for charge of metal ▫Metal is named first ▫Make sure to change the ending of the anion to -ide ▫After the name of the metal, the charge of the metal needs to be put in Roman numerals in parenthesis (because we can’t just look up the charge on the periodic table) ▫For example  FeCl 2 is ______________  Fe 2 O 3 is _____________  CrS is _______________

Other Ionic Compounds: Polyatomic Ions Polyatomic ions- two or more atoms combined that have an overall charge (form an ion) 2- CO NH 4 +

Polyatomic Names 10 Polyatomic Names to memorize Others can be built off of those names ▫Base is __________ ▫One less oxygen is ___________ For example: ▫NO 3 - is ______________ ▫NO 2 - is _____________

Compounds with Polyatomic Ions Can be ▫Type 1 metal (groups 1, 2, Al, Ag, Cd, or Zn) cation bonded with a polyatomic anion  For example: Mg(NO 3 ) 2, Cs 2 SO 4, Ca(IO 3 ) 2 ▫Type 2 metal (transition metal) cation bonded with a polyatomic anion  For example: NiSO 3, Fe 2 (CO 3 ) 3 ▫Or, a polyatomic cation bonded with a nonmetal (treat like a type 1)  NH 4 Cl, (NH 4 ) 2 O ▫All of these are ionic bonds

Creating Formulas for Compounds with Polyatomic Ions 1.Determine the charge of the cation and anion o Polyatomic ion- chart o Type 1 metal and nonmetals- determine charge from group # on periodic table o Type 2 metals- charge will be given to you 2.Determine how many ions of each type will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s or polyatomic ion’s symbol o If a subscript is placed after a polyatomic ion, the ion should be put in parenthesis with the subscript after it. 3.Make sure the formula is reduced to its simplest form

Creating Formulas for Compounds with Polyatomic Ions (cont) For example, ▫What is the formula for a compound made of potassium and the polyatomic ion hydroxide?

Creating Formulas for Compounds with Polyatomic Ions (cont) For example, ▫What is the formula for a compound made of gold (+2) and the polyatomic ion phosphate?

Creating Formulas for Compounds with Polyatomic Ions (cont) For example, ▫What is the formula for a compound made of the polyatomic ion ammonium and bromide?

Naming Compounds with Polyatomic Ions Compounds with ▫Type I metals and a polyatomic anion (base name without – ide)  Same as before except polyatomic ion name is the second name (do not change the ending to –ide)  For example: LiC 2 H 3 O 2 is lithium acetate ▫Type II metals and a polyatomic anion (base name without –ide but with Roman numeral)  Same as before except polyatomic ion name is the second name (do not change the ending to –ide)  For example: Sn(ClO 3 ) 2 is tin (II) chlorate ▫A polyatomic cation and a nonmetal (base name)  Polyatomic ion name comes first, the second name is the name of the nonmetal with the ending changed to –ide  For example: NH 4 F is ammonium fluoride