Review Of The Chem Quizzes Flashcards
3.5 billion years ago, single cells called ________ evolved, which invented a way to transduce solar energy into energy that could be stored in the form of a carbon-carbon bond. The chemical reaction that these organisms carried out is referred to as ___________ and produced _________ as a waste product. This product is toxic to anaerobic organisms that lived in the ocean at the time
Cyanobacteria
Photosynthesis
O2
To explain how the first snowball earth disappeared, it is believed that ______ played an important role because they released massive amounts of _______, which is an important _______.
Volcanoes
CO2
Greenhouse gas
Soon after the O2 concentration in the atmosphere reached present concentrations, photochemical process resulted in the formation of ______ in the atmospheric layer, which is referred to as the _______. This is important because this gas absorbs solar radiation in the ____ range, which protects organisms like sheep from forming cataracts.
O3
Stratosphere
200-300nm
the emission of man-made greenhouse gases into the troposphere will absorb/redirect the outgoing infrared radiation from Earth and thus result in a _________ radiative forcing. Conversely, the introduction of volcanic ash into the stratosphere would result in a __________ in incoming solar radiation and therefore correspond to a _________ radiative forcing
Positive
decrease
negative
the chemistry that forms the basis for the foundation of the ozone hole in the Antarctic involves converting two inactive forms of chlorine; ____ and _____ to CL2 on the surface of particles within polar stratospheric clouds. In the antarctic spring, a photochemical reaction will then convert this molecule to CL which will destroy massive amounts of O3 molecules according to _____________ (name mechanism)
HCl
ClONO2
mechanism II
The mechanism I of O3 destruction relies on ____ for the completion of the catalytic cycle and is therefore rather sluggish in the lower stratosphere. It follows the net overall reaction of: _______
oxygen radicals
O3 + O –> 2O2
although stratospheric O3 has been destroyed by natural compound catalysts that entered this atmospheric layer (e.g. CH3Cl emitted from the oceans) for millennia, this was eventually overshadowed by the massive release of man-made ____ into the atmosphere (1,000,000 t in 1980), which resulted in the formation of much larger quantities of inactive forms of chlorine
chlorofluorocarbons
the melting of the entire Greenland ice shelf (triggered by global warming) is dangerous because it would decrease the _____ of the seawater off the coast of Newfoundland/Greenland. this in turn would bring the _____ to a halt and is likely to cause the northern hemisphere to slip into the next ice age because heat will no longer dissipate to the polar regions but ocean currents
salinity
oceanic conveyer
molecular hydrogen (H2) is present in the atmosphere at an average concentration of 0.5 ppm. Since it is a homonuclear diatomic molecule, it isn’t associated with _______ and is therefore not a _____ gas.
dipole moment
greenhouse gas
Some scientists have suggested addressing climate change/global warming by an approach referred to as ‘CO2 sequestration.’ Briefly explain what this approach would consequently entail. Provide two examples of what some scientists have proposed to actually achieve this and how long-term sequestration without harming the ecosystem can be practically accomplished
when CO2 is removed from the air and deposited in an underground or ocean location that would prevent its release into the air.
ex. 1 – CO2 could be sequestered by burial in deep ocean waters, where it would dissolve, or in very deep aquifers under land or the seas, or in empty oil and natural gas wells or coal seams
ex. 2 – also planting more trees
in automobile exhausts, the most relevant pollutant gases from an environmental chemistry point of view are: ___, ____ and _______, which can be removed by ______. Nitric oxide, for example, is converted to innocuous gases following the chemical reaction: ______.
CO
NO
unburnt hydrocarbons
catalytic converters
2NO –> N2 +O2
_____ (DMS) is a gas that is naturally emitted from the ocean, and plays an important role in atmospheric chemistry. In the troposphere, it can be converted to ___, which can then diffuse into the stratosphere where it will be converted to ___, which results in the formation of ___. the latter will reflect incoming solar radiation to space and thus play a role in solar radiation management.
CH3-S-CH3 (dimethyl sulfide)
SO2
H2SO4
sulfate layer
the mortality rate of humans is most strongly correlated with the air quality parameter _____ because these ____ particles have a ____, which facilitates the transfer of carcinogens to lung cells.
PM2.5
respirable
large surface area
imagine that the analysis of aerosol particles has revealed a substantial fraction to be compared of NH4HSO4. Based on this chemical composition, there particles are classified as a ____ because their formation can be explained by the chemical reaction of _____, most likely emitted from agriculture
secondary aerosol
gaseous NH3
particulates in the air with a diameter of 0.01 um are referred to as ____. They are important in the context of atmospheric science because they are involved in the formation of ____.
Aitken nuclei
clouds
one of the 12 green chemistry principles states that the raw material feedstock that is used for the synthesis of a consumer product should not be _____, but rather ______. An example is the production of succinic acid which is increasingly produced from biobased materials instead of fossil fuels (e.g. oil)
depleting
renewable
