Rules and Naming Compounds Flashcards
1
Q
Insoluble rules of Ionic Compounds
A
- CO32- (Most carbonates)
- PO43- (Most phosphates)
- S2- (Most Sulfides)
- OH- (Most hydroxides)
exceptions:
- Group 1A carbohydrates (NH4)2CO3
- Group 1A phosphates (NH4)3PO4
- Group 1A sulfides (NH4)2S
- Group 1A hydroxides Ca(OH)2, Sr(OH)2, Ba(OH)2
1
Q
Naming Simple Compounds
A
- Usually contains a metal element and a non-metal element.
- Metal is usually listed first and is the name of the element.
- non-metal is listed second with its stem name and ends with a -ide suffix. e.g potassium bromide
2
Q
Oxidation-Number Rules
A
- Elements: Zero
- Monatomic ions: equals the charge on the ion
- Oxygen: -2 in most of its compounds, except for in peroxides, -1
- Hydrogen: +1 in most of its compound, except for in binary compounds with a metal, -1
- Halogen: flourines is -1 is in all its compounds. all other halogens is -1 unless it connect with other halogen above them, or the other element is oxygen.
- Compounds and ions: sum of the oxidation numbers of the atom in a compound is zero. the sum of the oxidation number in a polyatomic ion equals the charge.
3
Q
Naming Polyatomic Ions
A
No simple rules, there are a few pointers
- Cations are positioned first, then Anion
- Most are oxioanions, the names have a stem name plus a suffix -ate or -ite, greater number of oxygen atoms to the least number of oxygen atoms respectively
- if there is more than two as in oxianons of Cl
- Hypo- element -ite
- element -ite
- element -ate
- Per- element -ate
- Some are bonded with one or more Hydrogen atoms, sometimes called acid anions. If one H- atom, mono. if two H- , prefix di-
- If sulfur is attacthed, thio is the prefix
4
Q
Rules for predicting the charges on monatomic ions
A
- Most of the main group metallic elements have one cation with a charge equal to the group number in the periodic table
- Some metallic elements of high atomic number, have common cations equal to the group number minus 2, in addition to having a cation equal to the group number.
- Most transition elements form more than one cation, most are 2+.
- Charge on a monatomic anion for non-metallic element equals the group number minus 8.
5
Q
Rules for naming Monatomic ions
A
- cations are named after the element if there is only one ion
- If there is more than one cations, the stock system is used. Fe<span>2+</span> , is Iron (II)…
- Older system use an addition of suffics such as
- -ous: (lower charge)
- -ic: (higher charge)
- Older system use an addition of suffics such as
- Anions are named with the stem name with the suffix of -ide. e.g. Br- is Bromide
7
Q
Naming Binary Molecular Compounds
A
- The more metallic name is normally added first, then the non-metallic name. Placed in the order, from left to right on the periodic table.
- First element has its name, second element has the stem name of the element and an -ide as a suffix, as if it is an anion.
- Add a prefix to the element names to denote the subscripts.
8
Q
Solubility Rules for Ionic Compounds
A
- Li+, Na+,K+, NH4+ (Group 1A and ammonium compounds)
- C2H3O2-, NO- (Acetates and nitrates)
- Cl-,Br-,I- (Most chlorides, bromides, and iodides)
- SO42- (Most Sulfates)
Exceptions:
- AgCl, Hg2Cl2, PbCl2, AgBr, HgBr2, Hg2Br2, PbBr2, AgI, HgI2, Hg2I2, PbI2
- CaSO4, SrSO4, BaSO4, Ag2SO4, HgSO4, PbSO4
9
Q
Naming Hydrates
A
- Hydrates are named from the anhydrous compound, followed by the word hydrate with a prefix to indicate the number of water molecules per formula unit of the compound.
- CuSO4 → CuSO4 • 5H20, or Copper(II) Sulfate to Copper (II) Sulfate Pentahydrate
10
Q
Acids and Corresponding Anions
A
- An anion in a compound with a -ate suffix, is replaced with a -ic when an H proton is added.
- An anion in a compound with a -ite suffix, is replaced with a -ous, when an H proton is added.
Example: CO32- → H2CO32- , Carbonate ion now is a Carbonic acid