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Nomenclature. Naming and Formula Writing. Nomenclature. A term that describes the system of principles, procedures, rules, or terms related to naming. We use nomenclature to have a uniform set of rules for naming and writing formulas for chemical compounds.
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Nomenclature Naming and Formula Writing
Nomenclature • A term that describes the system of principles, procedures, rules, or terms related to naming. • We use nomenclature to have a uniform set of rules for naming and writing formulas for chemical compounds. • The IUPAC (International Union of Pure and Applied Chemistry) establishes these rules.
Review of Key Vocabulary • Ionic Compounds – contain bonds between metals and nonmetals • A bond involving a TRANSFER of electrons • A bond between cations and anions • Cation – An atom that has lost one or more electrons. It has a positive (+) charge. • Anion – An atom that has gained one or more electrons. It has a negative (-) charge.
More Key Vocabulary • Binary Compound – A substance that has only 2 different elements. • MgCl2 • NaCl • H2O • Ternary Compound – A substance that has 3 or more different elements. • NaOH • H2SO4 • CH3Cl
More Key Vocabulary • Prefix – A few letters placed at the beginning of a word to change its meaning. • Nonmetal • Carbon dioxide – CO2 • Carbon monoxide – CO
More Key Vocabulary • Ending / Suffix – A few letters placed at the end of a word to change its meaning. • Laughable • Portable • Calcium Sulfate – CaSO4 • Calcium Sulfite – CaSO3 • CalciumSulfide – CaS • Calcium Oxide - CaO
Ionic Nomenclature • Always write the cation and then the anion. • NaCl – NEVER ClNa • Sodium Chloride – NEVER Chloride Sodium
Binary Ionic Nomenclature (Formula Name) • 1-State the name of the cation • 2-State the name of the anion • For single elements, drop the ending, substitute the suffix–ide • Cl = Chlorine Chloride • F = Fluorine Fluoride • Br = Bromine Bromide • I = Iodine Iodide • O = Oxygen Oxide • S = Sulfur Sulfide • N = Nitrogen Nitride • P = Phosphorus Phosphide • C = Carbon Carbide
Practice Binary Ionic Naming • CaCl2 – Calcium chloride • MgO – Magnesium oxide • AlF3 – Aluminum fluoride • SrBr2 – Strontium bromide • Ba3N2 – Barium nitride
More Key Vocabulary • Subscript – A number that is written smaller and to the lower right of an element or group of elements telling you how many of that element or group there are. • H2O Mg(ClO3)2
More Key Vocabulary • Superscript – A number that is written smaller and to the upper right of an element or group of elements telling you the charge of the element or group of elements. • H3O+ Ca+2 SO4-2 N+3
Binary Ionic Nomenclature (Name Formula) • A little more difficult • 1 - Write the symbol of cation and anion including charge • 2 - Use subscripts to balance the charge of the compound • do not need to write a 1 – it is assumed • All ionic compounds have a neutral charge
Binary Ionic Nomenclature (Name Formula) • Calcium Bromide • Ca+2 Br- • There is a +2 charge and a -1 charge • An extra -1 charge is needed Ca+2 Br- Br- • +2 -1 -1 = 0 • Need 1 calcium and 2 bromine • CaBr2
“Crisscross” Method • Charge of thecationbecomes the subscript foranion • Charge of theanionbecomes the subscript for thecation • Aluminum Sulfide • Al+3 S-2 Al2S3 • Notice the + or – charge is dropped • Simplify to smallest whole numbers • Mg+2 O-2 Mg2O2 MgO Check Work
Practice Binary Ionic Formula Writing • Calcium Sulfide – CaS • Barium Chloride – BaCl2 • Lithium Fluoride – LiF • Aluminum Nitride – AlN • Sodium Phosphide – Na3P
More Key Vocabulary • Transition Element – An element in group 3 through 12 on the periodic table. • Oxidation State – A possible charge for an ion of a given element. • Located in top right corner of element square on PT • All “free elements” have oxidation states of ZERO • Many elements only have oneoxidation state • Many (BUT NOT ALL)transition elements have more than one oxidation state • Can have different charges! • Some, but only a few, other metals have multiple oxidation states
More Key Vocabulary • Roman Numerals – A numeral system established in ancient Rome. The system is based on certain letters which combine to signify a number. • 1 = I • 2 = II • 3 = III • 4 = IV • 5 = V • 6 = VI • 7 = VII
Binary Ionic Nomenclature Multiple Oxidation States (Formula Name) • Name theCation • In Parenthesis, write the oxidation number of thecationusingRoman Numerals • Name theAnion • Examples: Iron (II) oxide, Iron (III) oxide
Determining Oxidation NumberBased on Formula • We will use the “Multiply Down, Add Across” Method • First, rewrite the formula • Second, below each element, write the number of each element • Third, write any known charges, or write an “x” for an unknown charge • We typically know the charges for nonmetals • Group 15 = -3 • Group 16 = -2 • Group 17 = -1 • Fourth, multiply down, and then create an algebraic expression so you may add across.
Multiply Down, Add Across Fe2O3 FeO Charge of the Compound (Always 0, unless it is an ion) # of each element 2 3 1 1 Known Charges X -2 X -2 2X + -6 = 0 X + -2 = 0 2X = +6 X = +2 Solve X = +3 The oxidation state of Fe is +3 The oxidation state of Fe is +2 Iron (III) oxide Iron (II) oxide
Practice Binary Ionic Naming Using Elements w/. Multiple Oxidation States • MnBr4 – Manganese (IV) bromide • CoCl3 – Cobalt (III) chloride • Cr2O3 – Chromium (III) oxide • Ni3N2 – Nickel (II) nitride • TiS2 – Titanium (IV) Sulfide • Check to make sure the oxidation state you think is correct is a possible oxidation state according to your periodic table
Practice Binary Ionic Formula Writing Using Elements w/. Multiple Oxidation States • Easier than naming • Use the “crisscross” method • Remember to reduce subscripts… • Manganese (VII) sulfide – Mn2S7 • Chromium (VI) phosphide – CrP2 • Copper (II) chloride – CuCl2 • Platinum (IV) Oxide – PtO2
Final Key Vocabulary • Polyatomic Ion – A particle that contains more than one atom and has a positive or negative charge. • Table E • First 3 are cations, the rest are all anions
Ternary Ionic Nomenclature(Formula Name) • Same Rules • Write Cation first, then Anion • Polyatomic Ions have their own endings • NaClO2 = Sodium chlorite
Practice Ternary Ionic Naming • AgNO3 – Silver nitrate • CaSO4 – Calcium sulfate • Na2S2O3 – Sodium thiosulfate • Zn3(PO4)2 – Zinc phosphate • KMnO4 – Potassium permanganate • Hg2O – Dimercury (I) oxide • NH4Cl – Ammonium chloride • NH4OH – Ammonium hydroxide
Ternary Ionic Nomenclature(Name Formula) • Trickiest of them all… • 1 - Write the symbol of cation and anion including charge • This may mean a whole polyatomic ion • 2 - Use subscripts to balance the charge of the compound • do not need to write a 1 – it is assumed • 3 - Any subscripts for a polyatomic ion need to be written outside parenthesis that surround the polyatomic ion. • May still use “crisscross” method
Ternary Ionic Nomenclature (Name Formula) • Aluminum Sulfate • Al+3 SO4-2 • There is a +3 charge and a -2 charge • We need 2 +3 charges and 3 +2 charges • Al+3 Al+3 SO4-2 SO4-2 SO4-2 • +3 +3 -2 -2 -2 = 0 • Need 2 aluminums and 3 sulfates • Al2(SO4)2
“Crisscross” Method w/. Polyatomic Ions • Charge of the cation becomes the subscript for anion • Charge of the anion becomes the subscript for the cation • Iron (II) hydroxide • Fe+2 OH- • YOU NEED PARENTHESIS • There are not 2 H’s, there are 2 OH’s • Simplify to smallest whole numbers • Ca+2 S2O3-2 Ca2(S2O3)2 Check Work Fe(OH)2 CaS2O3
Practice Ternary Ionic Formula Writing • Calcium Sulfite – CaSO3 • Ammonium sulfide – (NH4)2S • Cobalt (III) phosphate – CoPO4 • Copper (II) nitrate – Cu(NO3)2 • Ammonium dichromate – (NH4)2Cr2O7
Ca3(PO4)2 Calcium phosphate NaOH Sodium hydroxide FeCl3 Iron (III) chloride CuSO3 Copper (II) sulfite KCN Potassium cyanide KBr Potassium bromide Sodium sulfide Na2S Barium nitride Ba3N2 Copper (II) peroxide CuO2 Manganese (VII) oxide Mn2O7 Strontium perchlorate Sr(ClO4)2 Chromium (III) nitrite Cr(NO2)3 Ionic Nomenclature Mega Practice
More Key Vocabulary • Covalent Compounds – contain bonds between one or two nonmetallic elements • Remember when Ionic Bonding was so short and easy, and Covalent Bonding was so long and tough? • OPPOSITE HERE • Naming Covalent Compounds is EASY
Covalent Prefixes • Only hard part: • You need to MEMORIZE these prefixes
Covalent Nomenclature(Formula Name) • Name the elements in the order they are listed • Use the prefixes to show how many of each element • DON’T use “mono” for the first element • Avoid difficulty saying words by eliminating “ao” or “oo” by just using “o” • Hexaoxide is too difficult to say, just write Hexoxide • Change the ending of the second element to -ide
Covalent Nomenclature Practice (Formula Name) • N2O – Dinitrogen monoxide • NO2 – Nitrogen dioxide • CO – Carbon monoxide • CO2 – Carbon dioxide • CCl4 – Carbon tetrachloride • NI3 – Nitrogen triiodide • ***NH3 – Ammonia • ***H2O – Water • CS2 – Carbon disulfide • N2O5 – Dinitrogen pentoxide *** There are common names for these we use instead, H2O you should know, NH3 is in your reference table…
Covalent Nomenclature (Name Formula) • Even Easier! • Use the prefixes to guide you for what the subscripts need to be • Dihydrogen monosulfide • Di = 2 H2 • Mono = 1 S • H2S
Covalent Nomenclature Practice (Name Formula) • Carbon tetrabromide – CBr4 • Iodine dioxide – IO2 • Phosphorus pentachloride – PCl5 • Dichlorine heptoxide – Cl2O7 • Diphosphorus trioxide – P2O3
Ionic + Covalent Nomenclature • The trick to naming and formula writing is determine first if the example is an ionic or covalent compound. Covalent Covalent Tetraphosphorus decoxide N2O Ionic Ionic Titanium (III) chloride (NH4)2S2O3 Ionic Covalent NH3 Ca3(PO4)2