Chapter 2 Nomenclature

Chemical Nomenclature Different types of compounds use different naming rules Chapter 2 – – – – Nomenclature Covalent Ionic Polyatomic ions Acids • Binary acids • Oxo Acids – Other molecules / with other naming rule which we will not cover: • Organic Molecules • Complex Ions Recognizing Bonding Patterns Recognizing Bonding Patterns Before you can name anything, you have to know what it is!! Before you can name anything, you have to know what it is!!
HCl (aq)
CO2
H2SO4
SO2
NaBr (aq)
NiCl2
H3PO4 (aq)
P2O5
H2O
BaSO4
KNO3
CoF3
CH3CH2CH3
HI NiCl2 NaBr CoF3 KNO3 BaSO4 CO2 H2O SO2 P2O5 Polyatomic Ions SO42PO43NO- (aq) Binary acids HCl (aq) HI (aq) Oxo-acids H2SO4 (aq) H3PO4 (aq) CH2OH CH3CH2CH3 Writing Ionic Formulas • What are the common charges of ions the following elements: potassium sulfur chlorine magnesium nitrogen cobalt silver zinc cadmium Covalent Organic Practice on Ionic Charges • • • • • • • • • Ionic Any binary ionic formula has two parts. A cation and an anion. A metal and a non-metal can usually form only one compound. To find the formula for… Many of these can be determined by their location on the periodic table. Others cannot! Na+ NaF 5 F- Notice that in both cases, the charges cancel Mg2+ ClMgCl2 Writing Ionic Formulas – “Short Cut” Writing Ionic Formulas – “Short Cut” Fe2+ Think of the “short-cut” method is a bit like cross-multiplication. Na+ F- Use the charge of the metal to give you the subscript of the nonmetal Na F Mg2+ Cl- Fe2O2 FeO Reduce Mg Cl2 Metal vs Nonmetal Ions This “reduce” rule is for ionic compounds. You do not want to “reduce” for covalent compounds. Common Charges for Main Group Ions Metal ions are named the same as neutral metal atoms. Na: sodium atom Na+: sodium ion If you use the “short-cut” method, you must reduce the subscripts to the lowest whole number ratio O2- Most of these charges can be deduced by looking at the group number Metals tend to lose electrons to become stable ions Nonmetal atoms and nonmetal ions differ in the suffix. -ide is added. F: fluorine atom F-: fluoride ion Non-metals tend to gain electrons to become stable ions Common Charges of the d-block Ionic Compounds These are the most common charges. Other charges are possible Can also be Cr6+ Can also be Co3+ Name of metal + name of non-metal ion Can also be Cu+ NaF Sodium Fluoride MgCl2 Magnesium Chloride FeO Iron (II) Oxide Fe2+ Fe3+ Fe2(SO4)3 Polyatomic ions are treated like any other monoatomic ion Iron (III) Sulfate Metals with more than one possible charge must be specified explicitly Polyatomic Ions Oxoanion Nomenclature Polyatomic ions are just…well…basically like they sound. Ions that have many atoms. In reality polyatomic ions are actually covalent molecules with an overall charge. 1 More oxygen per_____ate _____ate _____ite hypo_____ite Most common (draw the Lewis structure for nitrate) 1 Less oxygen Still fewer Some common polyatomic ions OHCH3COONH4+ CN- hydroxide acetate ammonium cyanide CO32NO3PO43SO42ClO3- carbonate nitrate phosphate sulfate chlorate • What is the name of NaClO? • What is the formula for sodium chlorate? • What is the name of FePO4? oxoanions 14 Writing Ionic Formulas – Polyatomic Ions Common Confusion Treat polyatomic ions the same as monoatomic ions when forming compounds. Polyatomic ions stay together as a unit. Fe2+ Polyatomic PO43- Use “()” for multiple polyatomic ions only Na+ NO3- Nitrate Nitrite Nitride NO3- NO2- N3- Sulfate Sulfite Sulfide 2- 2- SO4 Fe3(PO4)2 Na(NO3) Examples of Ionic Formulas Monoatomic SO3 S2- Phosphate Phosphite Phosphide PO43- PO33- P3- Ionic compounds • Write the formulas of compounds made by the following Ionic formulas pairs of ions. • Systematic names – Names given using established nomenclature system • Common names • • • • • • • Ba + Ba + Fe + Na + Mg + Zn + Al + – Names given before nomenclature system was devised – Many involved in mining / minerals Cl O Cl (HHMMM…what’s the trick here?) O NO3 F S • Examples – Lime, calcium oxide – Galena, lead (II) sulfide – Fluorite, calcium fluoride 17 CaO PbS CaF2 Ionic Compounds Binary Covalent Compounds: 2 Nonmetals Why do we need prefixes in covalent compounds? • Write formulas for the following names: – aluminum bromide – titanium(IV) chloride – chromium(III) sulfide Write the most metallic element first • Write names for the following formulas: – Ba3N2 – K2S – MnF2 Use prefixes to indicate number of atoms •Mono: 1 (monosyllabic) •Di: 2 •Tri: 3 (triathlon) •Tetra: 4 (tetris) •Penta: 5 (pentagon) •Hexa: 6 (hexagon) •Hepta: 7 •Octa: 8 (octagon) •Nona: 9 •Deca: 10 (decathlon) Never use mono for first element in name 19 Binary Covalent Compounds • Write formulas for the following names: – silicon tetrachloride – carbon monoxide – tetraphosphorus hexaoxide • Write names for the following formulas: – N2O4 – Cl2O7 – SF6 Although covalent, it is – H2S treated as H+ + S2– H2Se – NO2 Acids and Bases 20 Are the following names/formulas correct? • • • • • • • • Iron trichloride Magnesium monoxide Nitrogen oxide NaO Iron chloride Ferric (III) chloride Tin trichloride Iron chloride • • • • Sodium monoxide Iron (3) chloride Magnesium (II) oxide Carbon Sulfate Binary Acids (H+ + anion) • Hydrogen cation (H+), also called the proton • Hydroxide anion (OH-) Binary acids: acids with an H+ and an anion. hydro_____ic acid • Acid: substance that produces H+ in water – HCl, HNO3, H2SO4, H3PO4 – HCl dissolves in water  H+ (aq) + Cl- (aq) • Base: substance that produces OH- in water – NaOH, KOH, Ba(OH)2 – NaOH dissolves in water  Na+ (aq) + OH- (aq) • • • • • • Name the following acids: HBr (aq) HCl (aq) HI (aq) HF (aq) HCN (aq) Name of anion 24 Binary Acids Oxoacids The name and suffix of the oxoanion determines the name of the acid Oxoanion per_____ate _____ate Acid per_____ic acid _____ic acid _____ite _____ous acid hypo_____ ite hypo_____ous acid SO32- H2SO3 sulfite sulfurous acid 26 Oxoacid Nomenclature Nomenclature •diphosphorus tetraoxide •XeF4 •carbon tetrachloride •aluminum oxide •SnO2 •PbF2 •copper (II) nitrate •chromium (VI) oxide •H2SO3 (aq) •calcium carbonate •H2CO3 (aq) •iron (III) oxide •SiO2 •TiCl3 •sulfurous acid •P4O10 •carbonic acid •Cr2O3 •lead (II) chromate •HBr (aq) •hydrofluoric acid 28 Nomenclature Answers •P2O4 •xenon tetrafluoride •CCl4 •Al2O3 •tin (IV) oxide •lead (II) fluoride •Cu(NO3)2 •CrO3 •sulfurous acid •CaCO3 •carbonic acid •Fe2O3 •silicon dioxide •titanium (III) chloride •H2SO3 (aq) •tetraphosphorus decoxide •H2CO3 (aq) •chromium (III) oxide •PbCrO4 •hydrobromic acid •HF (aq)