Ch. 10 Representative Gases• Oxygen 02

–2 molecules of oxygen–What you breathe

• Ozone is a gas as O3

–3 molecules of oxygen–Ozone filters out U.V. light

• O2 & O3 are allotropes

–They have 2 or more different molecular forms of the element oxygen.

• Oxygen is needed for life, combustion of fuels, and energy.

• The ozone is destroyed by CFC’s, CO2, and other pollutants–O3 O2 + O

–Pollutants break down the ozone–This may cause global warming

• Oxygen is the most abundant element per mass on Earth.

• An oxide is a compound that contains O, which has a –2 charge.

• O2 is a peroxide

• A peroxide is a compound containing O2, which has a –1 charge.

• Which group is oxygen most likely to form with ?–Group 2 (+2 charge)

Hydrogen• Hydrogen is the most abundant element in

the universe.• Hydrogen is a highly efficient fuel in the

form of a gas.• Hydrogen may one day replace natural

gas if scientist figure a way to use hydrogen, so it is not as explosive.

• Hydrogen is the least dense element.• Hydrogen is found in more compounds

than any other element.

Nitrogen• Nitrogen as a gas is N2. It is the most

abundant gas in the Earth’s atmosphere.–Approximately 80 % atmosphere is

nitrogen.• Ammonia, which is made up of nitrogen and

hydrogen is an important fertilizer.• Nitrogen and Hydrogen are both odorless,

colorless, and tasteless gases.• Liquid nitrogen is formed at temperatures less

than –195 degrees C.

• Ammonia is a colorless gas with a strong odor and is harmful in high concentrations.–Ex. Household ammonia

• Production of ammonia–Haber process –N2 + 3H2 2NH3

Carbon Dioxide• Plays a major role in supporting plant

life and our life. Without plants we wouldn’t survive.

• We breathe out carbon dioxide as a waste product, which plants use for photosynthesis.–6CO2 + 6H2O C6H12O6 + O2

• Do you go a day without using plants?

• What produces more CO2? What reduces CO2?

• CO2 breaks down the ozone layer.• Carbon dioxide acts as an insulator

in the Earth’s atmosphere. The U.V. light that gets into the Earth’s atmosphere has a hard time getting back out of the atmosphere.

• Carbon dioxide is a colorless gas with a bit of a sour taste.

• Carbon dioxide does not combust or burn.• Carbon dioxide as a solid is dry ice

–-78.5 degrees C• Carbon dioxide as a liquid is in fire

extinguishers–Helps to reduce combustion

• Carbon dioxide as a gas is in pop.

• Carbon monoxide (CO) is a highly toxic compound produced as a by-product of many human activities and machines.

• CO is a poisonous gas.• CO is a colorless, tasteless, and

odorless gas–Hard to detect–Causes nausea and head-aches