High School Chemistry/Nomenclature of ionic, covalent compounds, acids, bases, and hydrates
Compound: A group of 2 or more elements chemically combined.
Covalent Compounds
editA covalent compound is a compound that is made out of neutral components (all nonmetals, such as H2O, CO2, C12H12O12), has low melting and boiling points (often gases and liquids at room temperature), has covalent bonds (shared electrons), and exists as individual molecules. Exceptions are made to BRINClHOF: Br2, I2, N2, Cl2, H2, O2, F2.
- Naming
- Count the number of atoms present of each nonmetal.
- Choose a Greek prefix:
Number | Greek Prefix |
---|---|
1 | Mono |
2 | Dri |
3 | Tri |
4 | Tetra |
5 | Penta |
6 | Hexa |
7 | Hepta |
8 | Octa |
9 | Nona |
10 | Deca |
Examples are...
- N2O5: Dinitrogen Pentaoxide
- CO: Carbon Monoxide
- Formulas
- Look at the Greek prefix.
- Assign the number and the elements attached.
Examples are...
- Dinitrogen Tetraoxide - N2O5
- Carbon Monoxide - CO
Ionic Compounds
editWhen you think of an ionic compound, think of salts, such as NaCl, CaCO3, and KF. These compounds generally have a metal and one or more nonmetals. They have cations and anions and these two cancel each other out since the nuclear change must equal 0. They have high melting and boiling points and transfer electrons (ionic bonds). These exist as crystal lattices (the term, unit cell, being the smallest crystal lattice).
Some compounds can be both covalent and ionic--the ionic compounds contain polyatomic ions. Polyatomic ions are groups of covalently bonded nonmetals which exist as ions. |
There are two types of ionic compounds: Binary and Ternary. Binary ionic compounds consist of a metal and nonmetal, while ternary ionic compounds consist of a metal and polyatomic ion. There are also binary and ternary ionic compounds that have transitional metals, and require roman numerals. Ternary ionic compounds with 2 polyatomic ions also exist as well.
EXCEPTIONS: Lead (Pb) and Tin (Sn) NEED ROMAN NUMERALS while Silver (Ag) and Zinc (Zn) DO NOT NEED ROMAN NUMERALS as their charge is always +1 and +2, respectively.
Binary Ionic Compounds
edit- Naming
- Name the metal ion.
- Name the nonmetal ion ending with -ide.
Examples are...
- NaCl: Sodium chloride
- LiCl: Lithium chloride
- Mg3N2: Magnesium nitride
- Formulas
- Determine the charge for each ion.
- Cross over
- Reduce
Examples are...
- CaCl2: Calcium Chloride
- KF: Potassium Flouride
- Li2O: Lithium Oxide
- Magnesium bromide: Mg2Br-1 → Mg1Br2 → MgBr2
- Calcium sulfide: Ca2S-2 → Ca2S2 → CaS
- Potassium chloride: K1Cl1 → K1Cl1 → KCl
With Transition Metals
edit- Naming
- Determine the charge.
- Name the transition metal.
- Put roman numerals and note the oxidation number of the transition metal (roman numeral in the chemical name gives the oxidation number of the metal ion).
- Name the nonmetal ion.
- Cross over.
Examples are...
- FeCl2 - Iron (II) chloride
- CuCl - Copper (I) chloride
- Cr2O3 - Chromium (III) oxide
- MnO - Manganese (II) oxide
- Formula
- The roman numeral in the chemical name gives the oxidation number of the METAL ion.
- Determine the metal ion.
- Determine the nonmetal ion.
- Cross over.
Examples are...
- CrCl3 - Chromium (III) chloride
- CuF2 - Copper (II) flouride
- CuF - Copper (I) flouride
- Iron (II) sulfide - Fe2S2 → FeS
- Iron (III) sulfide - Fe3S2 → Fe2S3
- Copper (II) oxide - Cu2O2 → CuO
Ternary Ionic Compounds
edit- Naming
- Name the metal
- Name the polyatomic ion
Examples are....
- LiNO3 - Lithium nitrate
- Mg3(PO4)2 - Magnesium phosphate
- KNO2 - Potassium nitrite
- CaSO4 - Calcium sulfate
- LiNO3 - Lithium nitrate
- Formulas
- Determine the oxidation number of the metal
- Write the formula for the polyatomic ion
- Cross over
Examples are...
- Srontium nitrate - Sr(NO3)2
- Magnesium sulfate - MgSO4
- Potassium perchlorate - KClO4
With Transition Metals
edit- Naming
- Determine the charge of the transition metal
- Determine the name of the polyatomic ion
- Name the transition metal ion
- Roman numeral indicates the charge on the transition metal
- Name the polyatomic ion.
Examples are...
- Cu(NO3)2 - Copper (II) nitrate
- MgSO3 - Magnesium (II) sulfate
- Formula
- Determine the charge on the transition metal.
- Write the formula for the polyatomic ion.
- Cross
Examples are...
- Chromium (II) phosphate - Cr3(PO4)2
- Iron (II) nitrate - Fe(NO3)2
- Copper (I) nitrate - Cu(NO3)
- Copper (II) perchlorate - Cu(ClO4)2
Ternary Ionic Compounds with 2 Polyatomic Ions
editThe polyatomic cation has to be ammonium (NH4). Name the ammonium, then the polyatomic ion.
Acids
editAcids always have an H in front of them; so it is easy. Examples are HCl, HBr, HClO4.
Binary Acids
editBinary Acids always have an H in front of them and are followed by a nonmetal (hydroanionic acid).
Ternary Acids
editTernary Acids do not have a hydro prefix in front of them (but they do have an H). You have to know your polyatomic ions in order to master the acids:
- If the polyatomic ion ends in -ate, the acid will end in -ic.
- If the polyatomic ion ends in -ite, the acid will end in -ous.
- If the polyatomic ion ends in -ide, the acid will be named hydroanionic acid.
Here is a great saying for you to remember this: I ate something icky. Don't bite -ous |
Examples are...
- HCl - Hydrochloric acid
- HBr - Hydrobromic acid
- HF - Hydroflouric acid
- HNO3 - Nitric acid
- HNO2 - Nitrous acid
- HPO3 - Phosphorous acid
- HCN - Hydrocyanic acid
Bases
editBases always have an OH-1 in front of them as the anion. This is known as the hydroxide.
- Naming
Examples are...
- KOH - Potassium hydroxide
- Ca(OH)2 - Calcium hydroxide
- Fe(OH)2 - Iron (II) hydroxide
- Formula
- Determine the oxidation number for the cation.
- Cross the oxidation number of the cation to the hydroxide
Examples are...
- Strontium hydroxide - Sr(OH)2
- Manganese (II) hydroxide - Mn(OH)2
Hydrates
editHydrates are made up of a salt and a H2O (water molecule).
- Naming and Formula
- Name the salt
- Name the prefix + hydrate
Examples are...
- Li2SO4 • 4H2O - Lithium sulfate tetrahydrate
- Na3PO4 • 5H2O - Sodium phosphate pentahydrate
- Copper (III) sulfate hexahydrate - Cu2(SO4)3 • 6H2O
- Copper (I) sulfate trihydrate - Cu2SO4 • 3H2O