Solubility Rules

Soluble means a substance will dissolve in water, whereas insoluble means it will not dissolve appreciably. If an insoluble product is created in an aqueous solution, it will precipitate out of solution as a solid.

Solubility Rules

Mainly soluble:

all nitrates & acetates

all halogens, except with silver, mercury and lead

all chlorates, except with silver, mercury and lead

all sulfates, except with calcium, strontium, barium, lead, mercury, and silver

all chromates, except with calcium, strontium, barium, lead, mercury, and silver

Mainly insoluble:

all sulfides, except with groups 1 & 2, and ammonium

all hydroxides, except with groups 1 & 2, and ammonium

all carbonates, except with group 1 and ammonium

all phosphates, except with group 1 and ammonium

Basic Types of Reaction

Synthesis (also called Addition, Composition and Combination)

     Atoms and or molecules are combined to make ONE more complex molecule.

A  +  B --> AB

Fe  +  S -->  FeS

metal oxide + water --> metal hydroxide

nonmetal oxide + water --> oxyacid

Decomposition (also called Analysis)

     A complex molecule is broken into simpler molecules and or atoms

AB --> A + B

KClO3 --> KCl  +  O2

metal chlorate --> metal chloride + oxygen

metal carbonate --> metal oxide + carbon dioxide

Single Replacement

     A single element replaces one component of a compound.  A metal must always replace a metal and a nonmetal must replace a nonmetal.  A single replacement replacement is a type of redox reaction where electrons are transfered from one atom to another.

A  + BX --> AX + B

K + CsCl --> KCl + Cs

X + AY --> AX  + Y

Cl2  +  MgBr2 --> MgCl2  +  Br2

Double Replacement (also called Ionic and Precipitation Reactions)

     Ionic compounds switch "partners."  Remember that a neutral compound must have a cation combined with an anion.

AX  +  BY --> AY  +  BX

CuCl  +  NaS --> CuS  +  NaCl

Reactions: Basics

Law of Conservation of Mass- Matter can neither be created nor destroyed, only rearranged in

a chemical reaction.

 Steps in balancing a chemical reaction:

1. predict the products in words

2. write the formula for all the reactants and products

(balance the charges and look for diatomic elements)

diatomic elements - H₂ , O₂ , N₂ , F₂ , Cl₂ , Br₂ , I₂

3. balance the polyatomic ions (nitrate. sulfate, hydroxide ...)

4. balance all other elements except hydrogen and oxygen

5. balance the hydrogen and oxygen  (don't forget to look for H and O in all compounds)

6. check every reaction again element by element 

Naming Acids

 All acids begin with a H⁺  and are combined with one of the three types of anions.

            -ide             to            hydro----ic acid                        H2S          hydrosulfuric acid

            -ate             to                        -ic acid                        H2SO4      sulfuric acid

            -ite              to                        -ous acid                     H2SO3      sulfurous acid

                        I -ate something and it made me s-ic.

                                        and you m-ite give it to -ous.

Ionic Compounds

Ionic compounds are formed between oppositely charged particles called ions.  Ions are formed when electrons are lost, called cations, or when electrons are gained, called anions.

A molecule must be neutral.  The total amount of positive charges must cancel out the total amount negative charges to create an overall charge equal to zero.

Covalent Compounds

Covalent bonds are formed by 2 or more atoms sharing electrons.  Typically this is between 2 non-metals since both atoms want to gain electrons to acquire a full outer shell.

To name covalent compounds, use the following prefixes to represent the subscripts and change the suffix of the more electronegative (always on the right) element to -ide.

1  mono

2  di

3  tri

4  tetra

5  pent

6  hex

7  hept

8  oct

9  non

10 dec

Isotopic Notation

Isotopes are atoms with the same number of protons but have a different number of neutrons.  They are basically different varieties of the same element.  Two of the most common isotopes that people hear about are Carbon-14 and Carbon-12.  Both isotopes are carbon because they each have 6 protons.  They are different because C-14 has 8 neutrons and C-12 only has 6.  While C-12 is the most abundant (common) isotope of carbon, both are called isotopes.

The number of protons in an atom is also called the atomic number.  The number of protons determines the identity of an atom, no matter how many neutrons or electrons are in the atom.  Atomic number is listed on the periodic table.  It is a whole number and is usually listed above the symbol for the element.  If you change the number of protons in an atom, the element has also changed.

Mass number is the total number of particles in the nucleus of an atom.  In other words, it is the number of protons plus the number of neutrons.  Isotopes have the same atomic number, but different mass numbers.  Mass numbers are NOT listed on the periodic table.  When you name a specific isotope, you MUST include its mass number, for instance Carbon-14 or Uranium-135.

The number below the symbol of the element on the periodic table is called the atomic mass.  It is the weighted average mass number of all the isotopes of a particular element.  Because it is an average, it has significant digits.

We can represent an isotope in an abbreviated form.  This is called the isotopic notation.

Here is the isotopic notation for carbon 14.

From looking at the isotopic notation, you can determine the number of protons, neutrons and electrons for a given atom.

In a neutral carbon 14 atom, how many protons, neutrons and electrons are there?
Protons- The atomic number is 6, therefore there are 6 protons
Electrons- If the atoms is neutral the number of protons equals the number of electrons, therefore there are also 6 electrons.
Neutrons- The mass number equals the number of protons + neutrons, therefore 14-6 leaves 8 neutrons.