Unit 5 Flashcards
What is the layer closest to the earths surface
Troposphere
what is the trosophere mafde of
The troposphere is made up of approximately 78% nitrogen molecules, 20% oxygen molecules, and 0.92% argon
How big is the troposphere
13 km
what is the last percent made up of
The last one percent is made up of water vapour, carbon dioxide, methane, and a cocktail of pollutants such as sulphur dioxide, nitrous oxide, chlorofluoro carbons, and smog.
what is the stratosphere
The stratosphere is the layer of atmosphere that sits on top of the troposphere. Whereas the gases are most dense at the surface of the Earth, they grow increasingly thinner the higher up you go.
wehat is the ozone
ozone (O3), which blocks up to 95% of the sun’s harmful UV rays (particularly UVC and B) that would otherwise strike the Earth and cause huge amounts of damage.
how is the ozone braking down
- humans have made chemicals that the sun can’t break down
- things like chlorofluro carbons (CFC)
give an example of a chemical that is breaking down the ozone layer
- trichlorofluro methane which is used in the coolent in freezers
- when the sunlight reacts with it it breaks down into a highly reactive radical that breaks down the ozone layer
what has helped with this recently
The Montreal protocol of 1987 led to many developed countries reducing CFCs and now the ozone hole is largely “healed”.
what is the air quality index
- Air Quality Index is the government’s measurement of the air quality in Ontario
what does it measure (air quality index)
- 200 sites around the province that sample air for gaseous containmenints and solid particles like dirt
what are the samples anaylised for
sulphur dioxide
ozone
CO (carbon monoxide)
what are the levels of sulphur dioxide (3)
- this pollutant is released in the gas emissions from oil and power generating stations, as well as smelters and industrial boilers.
- leading cause in acid rain
- levels must be less then 82 ppb
what are Levels of nitrous oxide
- This is produced by car and truck exhaust as well as fossil fuel burning power stations.
- It also causes the formation of acid rain and smog.
- Levels range from 15 to 51 (Windsor) ppb in Ontario.
what are the average levels of ozone in ON
30-47 ppb in Ontario
levels of carbon monoxide
this is a pollutant released when engines do not burn gas completely. It is poisonous to humans. Levels range from 0.3 to 1.10 ppb in Ontario.
Levels of particulate matter
Refers to a mixture of mineral or soil particles, ash, pollen etc. produced by such sources as incineration, forest fires, industry, heavy trucks
What season is the worse for particulater matter
summer
what is acid rain
cid precipitation refers to any release of acidified water from the air.
does it just have to be rain
no any form of percipitaion including snow and hail
what is the pH of acid rain normally
5.0
what can acid rain do?
Acid rain has the ability to kill lakes, forests, and streams, as well as damage buildings and statues.
where does ON acid rain come from?
Approximately 50% of the pollution that causes acid rain in Ontario comes from the U.S. — from the Ohio River Valley district with the prevailing southwesterly winds.
what is smog
common word for ozone
why is it a bigge problem in the summer
Smog (ozone) is a bigger problem in the summer months because the sunlight is stronger and helps VOCs and nitrous oxide to react more quickly
what does this smog cause in high concentratuions
higher occurrence of bronchitis, asthma, and heart attacks occur in regions with high levels of smog.
Acid rain formation equations
- sulfur undergoes oxidation to produce sulphur dioxide
S(s) + O2(g) —> SO2(g) - orderless, colourless gas is produced and reacts again with oxygen
SO2(g) + O2(g) —> SO3(g) - as it mixes in the air it combines with water droplest to produce sulfuric acid
- SO3(g) + H2O(l) —> H2SO4(g)
condictivity of acids and bases
both good electrolytes
reaction with carbonates acids
Reacts to produce CO2
reaction with carbonates bases
NR
reaction with reactive metals acids
reacts to produce H2 gas
reaction with reactive metals bases
NR
Litmus test
acids turn red
bases turn blue
methyl orange test
acids turn red
bases turn yellow
bromothymmol blue
acids turn yellow
bases turn blue
neutralization of acids
cancels out a base to make a salt and water
neutralization of bases
cancels out an acid to make a salt and water
pH range for an acid
0-6.9
pH range for a base
7.1-14
who came up with Arrhenius’s theroy
Swedish Scientist Svante Arrhenius in 1887
Arrhenius theroy definition acid
acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (H +)
Arrhenius theroy definition base
bases ionize in water to yield hydroxide ions (OH −).
What does arrhenius theroy say about the difference between week and strong acids
trong acids dissociate more or fully dissociate (produce more H+ ions) than weak acids
What does arrhenius theroy say about the difference between week and strong bases
Likewise, strong bases dissociate more or fully to produce more OH- ions
what determines if a pH number is low
A solution that has a large amount of hydrogen ions (H+) or protons will have a very low pH number
what determines if a pH number is high
a solution that has very few hydrogen ions will have a large pH number
how to use the logrithmic pH scale
each jump of a whole # is 10x more acidic or basic
what are the two types of acids
- Binary (in which there are only two symbols) such as HCl, HBr, HF, etc.
- Polyatomic acids (or oxyacids) e.g., H2SO4, H3PO4, H2CO3 , etc.
Give an example of a strong acid
hydrocholoric acid, nitric acid
Give an example of a weak acid
acetic acid, carbonic acid
Give an example of a strong base
calcium hydroxide, sodium hydroxide
Give an example of a weak base
calcium carbonate, ammonia
