air quality, climate and water Flashcards
what is the composition of clean dry air
78% nitrogen 21% oxygen and remainder is mixture of noble gases and carbon dioxide
name some air pollutants
carbo dioxide
carbon monoxide
particulates
methane
oxides of nitrogen
sulfur dioxide
where does carbon dioxide come from + its effects
complete combustion of carbon containing fuels
increased global warming leading to climate change
where does carbon monoxide and particulates come from + its effects
from incomplete combustion of carbon containg fuels
toxic gas, poisonous and particulates cause increased risk of respiratory problems leading to cancer
where does methane come from + its effects
the decomposition of vegetation and waste gases from digestion in animals
global warming leading to climate change
where does oxides of nitrogen come from + its effects
car engines
acid rain, photochemical smog and respiratory problems
where does sulfur dioxide come from +its effects
from the combustion of fossil fuels which contain sulfur compounds
acid rain
what are stratergies to reduce climate change
planting tress, reduction of livestock farming, decreasing use of fossil fuels, increasing use of hydrogen and renewable energy eg. wind, solar
what are stratergies to reduce acid rain
use of catalytic converters in vehicles, reducing emission of sulfur dioxide by using low-sulfur fuels and flue gas desulfurisation with calcium oxide
how do the greenhouse gases co2 and methane cause global warming
the absorption reflection and emission of thermal energy reducing thermal energy loss to space
how are oxides of nitrogen produced in car engines
in car engines where there is high temperature, nitrogen from air combines with oxygen in the air to produce NOx
how do catlytic converters work
harmful gases are absorbed onto surface of catlysts where they react to form harmless gases, catalysts speed up reaction
A- harmful compounds are reduced eg.
2No -> N2 + O2
B- harmful compounds are oxidised using oxygen from A
2CO + O2 -> 2CO2
harmless product flows out exhaust pipe
uses platinum or rhodium as catalyst onto ceramic honeycomb or ceramic beads
define photosynthesis
reaction between carbon dioxide and water to produce glucose and oxygen in the presence of chlorophyll and using energy from light
state word equation for photosynthesis
carbon dioxide + water -> glucose and oxygen
