CHM-131-160 Unit Three

Molecular/Covalent Compound
The smalles unit is a molecule, it is not made up of metals and it is electrically neutral.
Molecular Formula
Tells us how many atoms of each molecule are in a molecule/covalent compound.
Ionic Compound
Made of ions. When a group of ions have a charge, they are called polyatomic.
Formula Weight
the weight of the ion
Molecular Weight
the weight of the compound
Anion
negatively charged ion
Cation
positively charged ion
percent composition
determining mathematically what the percent a certain element contributes to the total weight
Combination Reaction
A + B = AB
Decomposition Reaction
AB = A + B
Combustion Reaction
hydrocarbon + O= H20 + CO2
Single Displacement
AB + C = AC + B
Double Displacement Reaction
AB + CD = AC + DB
Double Displacement Reaction – Precipitation
when two (aq) yield an (aq) and a (s)

Double Displacement Reaction – Gas Formation

When one of the products turns into a gas or decomposes into a gas.
Double Displacement Reaction – Neutralization
Acid + Base = Water + Salt
Properties of Acids
sour, react with metals and H2 gas
Properties of Bases
bitter and don’t react with metals
Acids
increase H concentration
Bases;
increase OH concentration
the seven strong acids

Hydrochloric Acid – HCl

Hydrobromic Acid – HBr

Hydroiodic Acid – HI

Nitric Acid – HNO3

Sulfuric Acid – H2SO4

Chloric Acid – HClO3

Perchloric Acid – HClO4

Alkali Metal Hydroxides

;

LiOH

NaOH

KOH

RbOH

CsOH

Alkaline Earth Metal Hydroxides

Ca(OH)2

Sr(OH)2

Ba(OH)2

Electrolyte

a substance forms ions in solution, then the solution conducts electricity

;

e.g. NaCl

Nonelectrolyte
Does not form ions in solution.