1. Representative Gases

2. Oxygen
Joseph Priestley
Name is Greek for “sharp” or “acid”

3. 21% of atmosphere
Almost 50% of earth’s crust
3rd most abundant in universe
Lewis structure
Colorless (blue), odorless, tasteless gas
Soluble in water

4. Reactive
Supports Combustion
Combines with Si, Al, Fe, Ca, Mg, etc. to form rocks and minerals

5. Necessary for life (respiration > photosynthesis)
Used in production of steel, plastics, and textiles
Rocket Propellant
Oxygen Therapy
SCUBA
Submarines/Aircraft

6. Ozone (O3) Name means, “to smell”
Found in upper atmosphere, ozone layer, and at the surface of the earth from car exhaust
Can be produced during lightning storms and by photocopiers
Poisonous blue gas, pungent odor

7. Ozone Concentrated gases can be dangerous
Destructive to plastics and lung tissue
Protects earth from UV rays
Detoxifies cyanides

8. Allotropes Element that exists in two or more forms in the same state
Oxygen and Ozone are allotropes
Graphite and Diamond are allotropes

9. Carbon Dioxide Trace amounts in atmosphere (0.039% by volume)
Colorless, odorless gas
Extinguishes flames
Important to life (photosynthesis, respiration), but can be toxic
Used in fire extinguishers, food additives, and as a refrigerant

10. Carbon Monoxide Colorless, odorless, tasteless gas Less dense than air
Largest amount of CO comes from photochemical reactions in the troposphere (lower atomosphere)
Produced from partial oxidation (incomplete combustion), naturally produced in volcanic eruptions and forest fires

11. Carbon Monoxide
Poisonous due to its interference with hemoglobin’s uptake of oxygen
Used as a modified atmosphere in meat packing (prevent discoloration)
Used in the production of detergents and acetic acid.

12. Hydrogen Name means “water former”
Most abundant element in the universe
Found as a gas on earth, plasma in stars
Reactive!

13. Colorless, odorless, tasteless
Rocket fuel (liquid)
Plasma in stars
Used in fossil fuel processing
Used to produce ammonia
Possible fuel of the future

14. Methane Less dense than air Colorless, odorless, tasteless
Burns with a blue flame (Bunsen burner)
Found underground and under the sea floor
Main component in natural gas
Concentration in the atmosphere is increasing, now is responsible for 20% of climate forcing (heat that is absorbed rather than radiated back to space)

15. Nitrogen

16. 78% of atmosphere
Colorless, odorless, tasteless
English word means “forming,” Greek word azote means “lifeless”
Non-reactive
Important to life
on earth
Nitrogen cycle
Used to produce nitric acid, ammonia, and explosives (TNT)
Refrigerant (liquid)

17. Ammonia Found only in trace quantities Colorless, strong smell
Capable of combustion
Acts as a weak base
Dissolves in water
Used in production of fertilizers and nitric acid
Used as a cleaner and refrigerant

18. Chlorine Yellow green in color Strong, bleach-like odor
3rd highest electronegativity, making it a strong oxidizer (reactive)
Careful when cleaning (bleach and ammonia)
Not found in nature as Cl2, found in earths crust as minerals like sodium chloride
Accounts for 1.9% of the ocean’s mass
Used to make bleach and as an early weapon
Historically used in photographic paper, silver chloride

20. Argon/Noble Gases Colorless, odorless, non-toxic
Third most common in the atmosphere <1% (2X more abundant than H2O and 20+X more abundant than CO2)
Comes from the decay of Potassium-40
Unreactive, few compounds have been made with Kr and Xe
Used as a shielding gas during welding, in lasers, and also in some fluorescent lighting.

21. Summary
Hydrogen, oxygen, and carbon dioxide are the “focus” gases, we made them in lab!
Be able to tell how each gas could be identified (color, odor, chemical test, physical property)
Know at least 2 uses for each gas
Be ready to draw Lewis structures for each gas (resonance included)
Know equations for how to produce the gases (one equation may be used for multiple gases).