Chapter 1

Why is there is there air?

Composition - OH

Atmospheric Pressure -OH
*Graph assignment - *

Pollutants - OH (Table 1.2)

Reading and Interpreting Tables


2% means 2 parts per hundred

2/100

In the case of atmospheric CO₂
.036% .036/100

Parts per million x/1,000,000

Set up a ratio:
.036/100 = x/1,000,000
x=360

Read Appendix 2

Classifying Matter

Mixture - Physical combination of two or more substances (air)

Chemical elements - substances that CAN NOT be broken down into simpler stuff by chemical means (Oxygen)

Chemical Compound - a pure substance made up of two or more elements in a fixed, chemical combination & composition (water, carbon dioxide)

USING THE PERIODIC TABLE

Atom- smallest unit of an element that can exist as a stable, independent entity.

Chemical Formulas - symbolic representation of the elementary composition of chemical compounds (H₂0,H₂)
_{Molecule - combination if a fixed number of atoms, held together by chemical bonds in a certain geometric arrangement.}

<sub>Chemical reaction - a process whereby substances (reactants) are transformed into different substances (products).

Chemical Equation (a model)

Reactant ----------->Product (-------->) “is converted to”, “yields”

TABLE 1.6 PG.17


Combustion of a Hydrocarbon</sub>

CH₄ + O₂ ---> CO₂ + H₂O
ALWAYS
Hydrocarbon + O₂ ---> CO₂ +H₂O

BURNING

In Chem we call it combustion. ALWAYS assume total combustion unless I tell you otherwise!!

CH₄ + O₂ --->

C₃H₈ + 0_{2 --->}

C₃H_{8 +} 5O_{2 --->} 3CO_{2 +} 4H₂O

YOUR CAR

C₈H₁₈ + O_{2 --->}


2C₈H_{18 +} 25O₂ ---> 16CO₂ + 18H₂0

BUT
If we don’t get enough O₂

2C₈H₁₈ + 17O₂ ---> 16CO + 18H₂O

Air Quality

Deadly Fog ---> New Stephen King Novel

1. Coal --> S 1-3%

2. Smokestacks --> hi vs. lo

3. Fine Particles

4. 2SO₂ + O₂ ---> 2SO₃ (Slow)

Catalyze - increase the rate of reaction

Aerosol - liquid droplets stay suspended in air (they are tiny --> fog)

5. H₂O + SO₃ ---> H₂SO_{4
The combination of separate components working together is greater than the summative effect of each individually
Synergism}

_{Octane +} O₂ ---> CO₂ + H₂O
<sub>if complete combustion otherwise

---></sub> CO + CO₂ + H₂O + xx
1. Not enough O₂
2. Not enough time

So your catalytic converter

2CO + O₂ ---> 2CO₂

<sub>US vs. world
we aren’t the best but we’re not the worst

Photochemical smog

Volatile Organic Compounds (VOCs) - these may be the bane of the next generation</sub>

NO, NO₂ in tables NO_{x
React with unburned gas to form ozone} (O₃)
_{Sunlight provides the Energy (E)}

_{risk assessment}
1. toxicity - amt. that is needed to do “damage” vs. LD50
10 ppb vs 10 pph

2. Exposure
a. Concentration in air (or?)
b. Time exposed
c. rate