470 likes | 808 Views
Chemical Nomenclature. 1. Binary Ionic Compounds - Type I 2. Binary Ionic Compounds - Type II 3. Ionic Compounds & Polyatomic (Complex) Ions 4. Hydrated Ionic Compounds 5. Binary Covalent Compounds 6. Binary Acids 7. Oxy-Acids. Definitions.
E N D
Chemical Nomenclature 1. Binary Ionic Compounds - Type I 2. Binary Ionic Compounds - Type II 3. Ionic Compounds & Polyatomic (Complex) Ions 4. Hydrated Ionic Compounds 5. Binary Covalent Compounds 6. Binary Acids 7. Oxy-Acids
Definitions • An IONIC COMPOUND consists of a metalcation bonded to a nonmetalanion. Electrostatic attraction holds them together. • A COVALENT COMPOUND consists of two nonmetal atoms sharing valence electrons. • A BINARY compound is one that is made of just two elements. There can be one of each element such as in NaCl or KF. There can also be several of each element such as Na2O or AlBr3.
Type I Binary Ionic Compounds • The metal cations in these compounds have only ONE possible charge. Na+ Zn2+ Al3+ Ca2+ sodium zinc aluminum calcium The charges are memorized or predicted using a periodic table! • The cations are bonded to nonmetal anions: O2- N3- F- Br - oxide nitride fluoride bromide Notice that simple anions are always named with the suffix “ide”
Predicting Charges on Monatomic Ions KNOW THESE !!!! +1 +2 -3 -2 -1 0 Cd+2
COMPOUNDS FORMED FROM IONS CATION + ANION ---> COMPOUND Na+ + Cl- --> NaCl A neutral compound requires equal number of + and - charges.
Naming Compounds Binary Ionic Compounds: • 1. Cation first, then anion • 2. Monatomic cation = name of the element • Ca2+ = calciumion • 3. Monatomic anion = root + -ide • Cl- = chloride • CaCl2 = calcium chloride
Naming Binary Ionic Compounds • Examples: NaCl ZnI2 Al2O3
Learning Check Complete the names of the following binary compounds: Na3N sodium ________________ KBr potassium ________________ Al2O3 aluminum ________________ MgS _________________________
Formulas for Binary Ionic Compounds • A binary compound is one made of two different elements. There can be one of each element such as in sodium bromide or potassium iodide. There can also be several of each element such as lithium oxide or aluminum bromide.
Writing FormulasFormula Unit – lowest whole number ratio of ions in an ionic compound • Points to remember about writing the formula from the name • The order in a formula is first the cation, then the anion. • You must know the charges associated with each cation and anion. • The sum of the positive charge and the sum of the negative charges MUST add up to zero. • You MAY NOT adjust the charges of the cations or anions to get a total charge of zero. • You MAY adjust the subscripts to get a total charge of zero.
Example #1 Suppose you must write the formula for sodium chloride. Write down the Na+ and Cl¯ right next to each other, as in this image: Move the positive charge (dropping the sign) to the subscript position of the anion: Move the negative charge (dropping the sign) to the subscript position of the cation: The result of all this moving is: Since subscripts of one are not written, but understood to be present, the final answer is:
Example #2 • Write the formula for aluminum oxide. • Write down the Al3+ and O2¯ right next to each other : • Move the positive charge (dropping the sign) to the subscript position of the anion: • Move the negative charge (dropping the sign) to the subscript position of the cation: • The result of all this moving is:
Learning Check Write the correct formula for the compounds containing the following ions: 1. Sodium sulfide a) NaS b) Na2S c) NaS2 2. Aluminum chloride a) AlCl3 b) AlCl c) Al3Cl 3. Magnesium nitride a) MgN b) Mg2N3 c) Mg3N2
Solution 1. Na+S2- b) Na2S 2. Al3+ Cl- a) AlCl3 3. Mg2+ N3- c) Mg3N2
Examples: Type I Binary Ionic Compounds • Write the formulas: • potassium oxide • zinc chloride • silver sulfide • aluminum nitride • gallium oxide • calcium iodide • Write the names: • K3N • AgI • ZnBr2 • Al2O3 • Ba3P2 • LiH
Transition Metals Elements that can have more than one possible charge MUST have a Roman Numeral to indicate the charge on the individual ion. 1+ or 2+ 2+ or 3+ Cu+,Cu2+ Fe2+, Fe3+ copper(I) ion iron(II) ion copper (II) ion iron(III) ion
Names of Variable Ions These elements REQUIRE Roman Numerals because they can have more than one possible charge: anything except Group 1A, 2A, Ag, Zn, Cd, and Al (You should already know the charges on these!) Or another way to say it is: Transition metals and themetalsin groups 4A and 5A (except Ag, Zn, Cd, and Al) require a Roman Numeral. FeCl3(Fe3+) iron (III) chloride CuCl (Cu+ ) copper (I) chloride SnF4 (Sn4+) tin (IV) fluoride PbCl2 (Pb2+) lead (II) chloride Fe2S3 (Fe3+) iron (III) sulfide
Learning Check Complete the names of the following binary compounds with variable metal ions: FeBr2 iron (_____) bromide CuCl copper (_____) chloride SnO2 ___(_____ ) ______________ Fe2O3 ________________________ Hg2S ________________________
Examples: Type II Binary Ionic Compounds • Write the formulas: • iron (II) oxide • copper (II) chloride • tin (IV) sulfide • cupric nitride • nickel (III) oxide • ferrous iodide • cobalt (III) selenide • Write the names: • Fe2O3 • SnS • NiBr2 • CuS • Pb3P2 • CuBr • FeCl3
Formulas of Ionic Compounds Formulas of ionic compounds are determined from the charges on the ions atoms ions – Na + F : Na+ : F : NaF sodium + fluorine sodium fluoride formula Charge balance: 1+1- = 0
Polyatomic Ions NO3- nitrate ion NO2- nitrite ion
Polyatomic (Complex) Ions • All of the cations and anions so far have been simple ions - single atoms that have lost or gained electrons. • Complex polyatomic ions may be cations or anions. examples: nitrate: NO3- sulfate: SO42- hydroxide: OH-
NH4+ Cl- IONIC COMPOUNDS ammonium chloride, NH4Cl
Things to Notice • Most complex ions are anions. Ammonium, NH4+, is the most common complex cation. • Several complex ions form a short series of ions. The ions differ only in the number of oxygen atoms: perchorate ClO4- sulfate SO42- chlorate ClO3- sulfite SO32- chlorite ClO2- hypochlorite ClO- nitrate NO3- nitrite NO2-
If an ion carries a charge like “-2” or “-3”, a series of related ions can be formed by adding hydrogen cations (H+) while still leaving a net charge: examples: Sulfide: S2- hydrogen sulfide: HS- (bisulfide) Sulfate: SO42- hydrogen sulfate: HSO4- (bisulfate) Carbonate: CO32- hydrogen carbonate: HCO3- (bicarbonate) Phosphate: PO43- hydrogen phosphate: HPO42- dihydrogen phosphate: H2PO4-
Ionic Compounds containing Polyatomic Ions Writing Formulas • Write each ion, cation first. Don’t show charges in the final formula. • Overall charge must equal zero. • If charges cancel, just write symbols. • If not, use subscripts to balance charges. • Use parentheses to show more than one of a particular polyatomic ion. • Use Roman numerals to indicate the ion’s charge when needed (stock system)
Learning Check 1. aluminum nitrate a) AlNO3 b) Al(NO)3 c) Al(NO3)3 2. copper(II) nitrate a) CuNO3 b) Cu(NO3)2 c) Cu2(NO3) 3. Iron (III) hydroxide a) FeOH b) Fe3OH c) Fe(OH)3 4. Tin(IV) hydroxide a) Sn(OH)4 b) Sn(OH)2 c) Sn4(OH)
Writing formulas with Complex Ions a) Ammonium chloride b) Silver sulfate c) Aluminum hydroxide d) Calcium phosphate e) Iron (III) nitrite f) Copper(II) permanganate g) Ammonium dichromate h) Zinc acetate
More Formulas with Complex Ions a) NaHCO3 b) Ni(HS)2 c) Al(ClO4)3 d) Ba(H2PO4)2 e) Fe2(SO2)3 f) CuHSO4 g) Zn(IO4)2
Mixed Practice! Name the following: • Na2O • CaCO3 • PbS2 • Sn3N2 • Cu3PO4 • HgF2
Mixed Up… The Other Way Write the formula: • Copper (II) chlorate • Calcium nitride • Aluminum carbonate • Potassium bromide • Barium fluoride • Cesium hydroxide
Naming Molecular Compounds All are formed from two or more nonmetals. CO2 Carbon dioxide Ionic compounds generally involve a metal and nonmetal (NaCl) BCl3boron trichloride CH4 methane
Binary Covalent Compounds • Covalent compounds are made of two NONMETAL elements sharing valence electrons. • There are no ions involved!! • Because there are no charges to help us write the formulas of covalent compounds, prefixes are used to indicate the number of each atom present in the formula. • The first element receives a prefix if the subscript is greater than one. The second element ALWAYS gets a prefix.Change the ending of the second element to -ide. The prefix, “mono” is never used for the first element in the formula!
Molecular (Covalent) Nomenclaturefor two nonmetals • Prefix System (binary compounds) CO2 is named “carbon dioxide” CO is named “carbon monoxide” N2O is named “dinitrogen monoxide” SO3 is named “sulfur trioxide” .
PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER 1 2 3 4 5 6 7 8 9 10 Molecular Nomenclature Prefixes
Molecular Nomenclature: Examples • CCl4 • N2O • SF6
More Molecular Examples • arsenic trichloride • dinitrogen pentoxide • tetraphosphorus decoxide
Learning Check Fill in the blanks to complete the following names of covalent compounds. CO carbon ______oxide CO2 carbon _______________ PCl3 phosphorus _______chloride CCl4 carbon ________chloride N2O _____nitrogen _____oxide
Learning Check 1. P2O5a) phosphorus oxide b) phosphorus pentoxide c) diphosphorus pentoxide 2. Cl2O7 a) dichlorine heptoxide b) dichlorine oxide c) chlorine heptoxide 3. Cl2 a) chlorine b) dichlorine c) dichloride
Binary Acids • A simple definition of an “acid” is a substance which produces H+ ions in water. • Most acids have hydrogen ions in their formulas. • A binary acid composed of a hydrogen cation bonded to one other element: HCl HBr H2S hydrochloric acid hydrobromic acid hydrosulfuric acid Binary acids are always named: hydro____ic acid
Oxy-Acids • An acid can also be made of a hydrogen ion bonded to a complex ion. Complex ions whose names end in “ate”: NO3- SO42- CO32- PO43- nitric acid: HNO3 sulfuric acid: H2SO4 carbonic acid: H2CO3 phosphoric acid: H3PO4 Can you propose a rule for naming oxy-acids with complex ions ending in “ate”?
More Oxy-Acids • Complex ions ending in “ite”: NO2- SO32- ClO- ClO2- nitrous acid: HNO2 sulfurous acid: H2SO3 hypochlorous acid: HClO chlorous acid HClO2 Can you propose a rule for naming oxy-acids with complex ions ending in “ite”?
Hydrated Ionic Compounds • A HYDRATE is an salt that has water molecules trapped within its crystals. • Every hydrate has a certain number of water molecules associated with each formula unit of the ionic compound. The number of water molecules is indicated by using prefixes. mono hexa di hepta tri octa tetra nona penta deca CuSO4 · 5 H2O copper (II) sulfate pentahydrate MgCO3 ·10 H2O magnesium carbonate decahydrate
Examples of hydrates: • Write the formulas: copper(II) fluoride tetrahydrate CuF2·4 H2O calcium nitrate trihydrate Ca(NO3)2 ·3 H2O • Write the names: MgSO4· 7 H2O magnesium sulfate heptahydrate FeCl2 · H2O iron (II) chloride monohydrate