APES Chemistry Review
Abbreviations
- VOC = volatile organic compounds (some VOCs are hydrocarbons)
- PAN = peroxyacyl nitrates
- PAH = polycyclic aromatic hydrocarbons
- pH = potential (or power) of the hydrogen ion. pH = -log[H+] indicating that a low pH value (less than 7) is an
acid and a high pH value (more than 7) is a base.
- Hydrocarbons: molecules that contain carbon and hydrogen ONLY (some hydrocarbons are VOCs)
- CFC = chlorofluorocarbon, compounds that contain carbon, chlorine, and fluorine ONLY, such as CCl2F2, CCl3F,
and so on.
- DO = dissolved oxygen
Formulas to Know
- C = carbon
- U = uranium
- U-235 = the uranium
isotope preferred for
nuclear power plants
- U-238 = the most
commonly found uranium
isotope
- Cl2 = chlorine
- O2 = oxygen
- O3 = ozone
- N2 = nitrogen
- H2 = hydrogen
-
-
-
P = phosphorous
PO4-3 = phosphate
S = sulfur
NOx = nitrogen oxides
(including NO nitric oxide
and NO2 nitrogen dioxide)
SOx = sulfur oxides
(including SO2 sulfur
dioxide and SO3 sulfur
trioxide)
NH3 = ammonia
NH4+1 = ammonium
NO3-1 = nitrate
-
NO2-1 = nitrite
-2
SO4 = sulfate
H2SO4 = sulfuric acid
HNO3 = nitric acid
CO2 = carbon dioxide
CO3-2 = carbonate
H2O = water
CH4 = methane (natural
gas)
CaCO3 = calcium
carbonate (limestone)
pH
 pH is the negative log of the hydrogen ion concentration (sometimes called the potential of hydrogen ion).
 Mathematically it is represented by the equation: pH = –log[H+] or pH = –log[H3O+]
 [H+] is the molarity (# of moles per liter) of H+ ions
 [H+] and [H3O+] are essentially the same. H3O+ is called the hydronium ion, it results when H+ are in water.
 Low pH corresponds to being more acidic. High pH corresponds to being more basic.
 The opposite of acidic is basic.
 The range of pH is from 0 to 14.
pH=1 \ [H+]=1 x 10-1 moles/liter (very acidic)
pH=4 \ [H+]=1 x 10-4 moles/liter (acidic)
pH=6 \ [H+]=1 x 10-6 moles/liter (slightly acidic)
pH=7 \ [H+]=1 x 10-7 moles/liter (neutral)
pH=8 \ [H+]=1 x 10-8 moles/liter (slightly basic)
pH = 13 \ [H+]=1 x 10-13 moles/liter (very basic)
Basics
-
Neutrons, protons, and electrons are the components of atoms, which combine to form molecules.
-
The basic unit of all chemical compounds, whether natural or man-made, is the molecule.
Photosynthesis and Respiration (Note that these reactions are opposite processes.)
6CO2 + 6H2O + energy → C6H12O6 + 6O2 photosynthesis C6H12O6 + 6O2 → 6CO2 + 6H2O + energy cellular respiration