Chemical Naming & Formula Writing How do you do this???

What are Ionic Compounds? Ionic compounds consist of a cation (+ ion) and an anion (- ion) Monotomic cations can be found to the left of the staircase Monotomic anions can be found to the right of the staircase Ex: NaCl, CaBr 2, K 3 P

Polyatomic Ions Can be found on the back of the periodic table Groups of elements that are covalently bonded that have an overall charge Only one polyatomic ion that is cationic (+) NH 4 + = ammonium  All others are anionic (-)  Examples include: CO 3 -2, C 2 H 3 O 2 -1, PO 4 -3

Examples Of Ionic Compounds With Polyatomics NH 4 Cl Ca(OH) 2 Cu 3 (PO 4 ) 2 HC 2 H 3 O 2 KIO 3 NaHCO 3 Mn(CN) 4

How are Ionic Compounds Bonded? Ionic compounds are formed when electrons are transferred between the cation and anion The cation will lose electron(s) to become stable and look like a noble gas The anion will gain electron(s) to become stable and look like a noble gas

Tug Of War Bonding is like tug of war. In an ionic bond, the metal will lose it’s end of the rope to the nonmetal. The “loser” is the metal and the “winner is the “nonmetal”. Metal Nonmetal

How is NaCl Formed? Na Cl Na has 1 valence electron and Cl has 7 valence electrons. Na will transfer its 1 valence electron to Cl so that they can both become stable and look like noble gases. Na +1 now looks like Ne from the outer shell and Cl -1 now looks like Ar.

What Does an Ionic Formula Represent? An ionic formula represents the lowest whole number ratio of atoms in a compound This ratio is referred to an a formula unit Na+ (green) ions will ionically bond with Cl- (purple) ions in a repeating pattern toform what is called a crystal lattice.A formula unit is the lowest whole numberratio of the Na to Cl atoms which would be 1:1  NaCl. Na+ (green) ions will ionically bond with Cl- (purple) ions in a repeating pattern toform what is called a crystal lattice.A formula unit is the lowest whole numberratio of the Na to Cl atoms which would be 1:1  NaCl.

Unique Properties of Ionic Compounds? Solids at room temperature Relatively high melting points (>300°C) High solubility in water No conductivity as a solid but as an aqueous solution or molten, they are conductive You must have ions present in order to conduct electric current

How To Write Formulas For Ionic Compounds Cation always comes first Put together in the proper ratio where no charge remains on the compound when electron transfer is complete. Put parentheses around polyatomic ions when more than 1 is needed in a compound.

Examples of Writing Ionic Formulas

How To Name Cations Monotomic cations that only have 1 charge: – metal name + ion Transition metals with multiple charges – Stock Method: – metal name + (roman numeral of charge) + ion Transition metals with multiple charges – Traditional Method: – Latin stem name + ous + ion *lower charge ion – Latin stem name + ic + ion *higher charge ion Monatomic anions

Examples

How To Name Anions Monatomic anions: – Nonmetal stem name + ide + ion Polyatomic ions: – Name listed on back of periodic table + ion

Examples

Examples Of Naming Ionic Compounds

What are Covalent/Molecular Substances? Molecular compounds/substances consist of 2 nonmetals located to the right of the staircase 2 types: polar and nonpolar covalent Polar covalent compounds usually are made up of 2 or more different nonmetals Ex: H 2 O, NH 3, CO Nonpolar covalent substances usually are made up of 2 of the same nonmetals (diatomic) Ex: Br 2, O 2, H 2, N 2, F 2, I 2, Cl 2

How are Molecular Compounds/Substances Formed? For polar covalent compounds, electrons are unequally shared between the nonmetals to achieve noble gas stability The higher electronegative element will pull the electron(s) its sharing closer to it than the less electronegative element For nonpolar covalent substances, electrons are equally shared between the nonmetals to achieve noble gas stability

Polar Covalent Bonds The tug of war rope is now shared between the 2 nonmetals on either end of the rope. The nonmetal will a higher electronegative value will pull the rope more than the less electronegative end. Less Electronegative Nonmetal More Electronegative Nonmetal

Non Polar Covalent Bonds The tug of war rope is shared between the 2 nonmetals on either end of the rope. Both nonmetals have either the same/similar electronegative values, therefore will be pulling on the rope with the same force. Stalemate!

Nonpolar covalent equal sharing of an electron between 2 F atoms to become more stable and look like Ne F2F2 H2OH2O Polar covalent unequal sharing of an electron between each of the 2 H atoms and the O atom allows H to look like He and O to look like Ne. The electrons are pulled closer to because it is the more electronegative element

What Does a Molecular/Covalent Formula Represent? A molecular formula represents the actual number of atoms in a compound There are 2 H and 1 O atoms in 1 water molecule There are 3 H and 1 N atoms in 1 ammonia molecule

Unique Properties of Polar Covalent Compounds? Usually liquids or gases at room temperature Melting point is <300°C (less than ionic) Solubility in water varies Not conductive

How To Name/Write Formulas For Covalent Compounds For the first nonmetal: – Greek prefix (except mono) + nonmetal name For the second nonmetal: – Greek prefix + nonmetal stem name + “ide” Greek prefixes are found on the back of the periodic table. They are used to denote the number of atoms of that element. The number of atoms of that element is displayed as a subscript proceeding the element symbol.

Examples Of Covalent Compounds

Unique Properties of Nonpolar Covalent Substances? Gases at room temperature (exceptions include I 2 solid and Br 2 liquid ) Very low melting point (less than polar covalent) No solubility in water Not conductive

Diatomic Elements Keep Their Name! Br 2 = bromine O 2 = oxygen H 2 = hydrogen N 2 = nitrogen F 2 = fluorine I 2 = iodine Cl 2 = chlorine

What are Metallic Substances? Made up of only metals Ex: Cu, Pt, Sn, Pb, Ag Metallic substances made up of more than 1 metal are called alloys Ex: brass (70% Cu & 30% Zn), stainless steel, pewter, 14K-24K Au Metallic bonding and properties video: Stainless steel alloy video:

How are Metallic Bonds Formed? Metallic substances are bonded by a sea of electrons that hold the metal cations together The delocalized electrons do not belong to any single cation. They swim in the sea, holding the cations together

What Does a Metallic Formula Represent? Like an ionic formula, metallic formulas also represent the lowest whole number ratio of atoms in the structure This ratio is referred to an a formula unit

Unique Properties of Metallic Compounds? Solids at room temperature (exception Hg liquid ) Very high melting points (higher than ionic) No solubility in water Conductive because of the mobile ions swimming in the sea of delocalized electrons