Rules and Naming Compounds

Question 1

Insoluble rules of Ionic Compounds

Answer 1

1. CO₃^2- (Most carbonates)
2. PO₄^3- (Most phosphates)
3. S^2- (Most Sulfides)
4. OH^- (Most hydroxides)

exceptions:

1. Group 1A carbohydrates (NH₄)₂CO₃
2. Group 1A phosphates (NH₄)₃PO₄
3. Group 1A sulfides (NH4)₂S
4. Group 1A hydroxides Ca(OH)₂, Sr(OH)₂, Ba(OH)₂

Question 1

Naming Simple Compounds

Answer 1

• 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

Question 2

Oxidation-Number Rules

Answer 2

1. Elements: Zero
2. Monatomic ions: equals the charge on the ion
3. Oxygen: -2 in most of its compounds, except for in peroxides, -1
4. Hydrogen: +1 in most of its compound, except for in binary compounds with a metal, -1
5. 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.
6. 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.

Question 3

Naming Polyatomic Ions

Answer 3

No simple rules, there are a few pointers

1. Cations are positioned first, then Anion
2. 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
3. if there is more than two as in oxianons of Cl
   
   1. Hypo- element -ite
   2. element -ite
   3. element -ate
   4. Per- element -ate
4. Some are bonded with one or more Hydrogen atoms, sometimes called acid anions. If one H^- atom, mono. if two H^- , prefix di-
5. If sulfur is attacthed, thio is the prefix

Question 4

Rules for predicting the charges on monatomic ions

Answer 4

1. Most of the main group metallic elements have one cation with a charge equal to the group number in the periodic table
2. 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.
3. Most transition elements form more than one cation, most are 2⁺.
4. Charge on a monatomic anion for non-metallic element equals the group number minus 8.

Question 5

Rules for naming Monatomic ions

Answer 5

1. cations are named after the element if there is only one ion
2. If there is more than one cations, the stock system is used. Fe^{<span>2+</span>} , is Iron (II)…
   
   1. ​Older system use an addition of suffics such as
      
      1. ​-ous: (lower charge)
      2. -ic: (higher charge)
3. ​​Anions are named with the stem name with the suffix of -ide. e.g. Br^- is Bromide

Question 7

Naming Binary Molecular Compounds

Answer 7

1. 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.
2. 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.
3. Add a prefix to the element names to denote the subscripts.

Question 8

Solubility Rules for Ionic Compounds

Answer 8

1. Li⁺, Na⁺,K⁺, NH₄⁺ (Group 1A and ammonium compounds)
2. C₂H₃O₂^-, NO^- (Acetates and nitrates)
3. Cl^-,Br^-,I^- (Most chlorides, bromides, and iodides)
4. SO₄^2- (Most Sulfates)

Exceptions:

3. AgCl, Hg₂Cl₂, PbCl₂, AgBr, HgBr₂, Hg₂Br₂, PbBr₂, AgI, HgI₂, Hg₂I₂, PbI₂
4. CaSO₄, SrSO₄, BaSO₄, Ag₂SO₄, HgSO₄, PbSO₄

Question 9

Naming Hydrates

Answer 9

1. 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.
2. CuSO₄ → CuSO_{4 •} 5H₂0, or Copper(II) Sulfate to Copper (II) Sulfate Pentahydrate

Question 10

Acids and Corresponding Anions

Answer 10

1. An anion in a compound with a -ate suffix, is replaced with a -ic when an H proton is added.
2. An anion in a compound with a -ite suffix, is replaced with a -ous, when an H proton is added.

Example: CO₃^2- → H₂CO₃^2- , Carbonate ion now is a Carbonic acid