10. air Flashcards
1
Q
composition of air
A
- 78% nitrogen
- 21% oxygen
- 0.03% carbon dioxide
- <1% other gases (group 0 noble gases)
2
Q
common atmospheric pollutants
A
- carbon monoxide
- nitrogen monoxide + nitrogen dioxide
- sulfur dioxide
- methane gas
- unburnt hydrocarbons
- carbon dioxide
3
Q
carbon monoxide:
source
A
- incomplete combustion of carbon containing fuels
4
Q
carbon monoxide:
effects on humans
A
- toxic to humans
- binds to haemoglobin in RBCs to form carboxyhaemoglobin
- irreversible reaction, reduces ability of RBCs to transport oxygen
- death
5
Q
carbon monoxide:
solutions
A
- removed by reactions in catalytic converters in vehicles
- CO + O2 = CO2
6
Q
nitrogen monoxide + nitrogen dioxide:
source
A
- lightning activities
- in internal combustion engines
- high temperature causes nitrogen and oxygen in the atmosphere to react
- nitrogen monoxide can oxidise easily to form nitrogen dioxide
7
Q
nitrogen monoxide + nitrogen dioxide:
effects on environment
A
- nitrogen monoxide: neutral
- nitrogen dioxide: acidic gas
- dissolves in rainwater to form nitrous acid, oxidised to form nitric acid
- acid rain
8
Q
impacts of acid rain
A
- corrodes buildings made of cement, reactive metals and limestone
- decreases pH in soils, unsuitable for growing crops, reducing crop yield
- may fall into rivers and lakes, decreasing pH of water and affecting plants + marine life
9
Q
nitrogen monoxide + nitrogen dioxide:
effects on humans
A
- poisonous choking gas that irritates and attacks the lungs
- respiration problems
10
Q
nitrogen monoxide + nitrogen dioxide:
solutions
A
- removed by reactions in catalytic converters in internal combustion engines
- decomposes in a redox reaction to form N2 and O2
- NO can react with CO to form CO2 and H2O
11
Q
sulfur dioxide:
source
A
- volcanic eruptions
- incomplete combustion of fossil fuels in internal combustion engines
12
Q
sulfur dioxide:
effects on environments
A
- acidic oxide
- dissolves in water to form sulfurous acid, which oxidises to form sulfuric acid
- acid rain
13
Q
impacts of acid rain
A
- corrodes buildings made of cement, reactive metals and limestone
- decreases pH of soil, unsuitable for growing crops, reducing crop yield
- may fall into rivers or lakes, affecting pH of water and plant/marine life
14
Q
sulfur dioxide:
effects on humans
A
- poisonous choking gas that irritates and attacks the lungs
- respiratory problems
15
Q
sulfur dioxide:
solutions
A
- removed in flue glue desulfurisation to reduce liberation of sulfur dioxide gas
- flue glue: waste gas from combustion of fossil fuels
- sulfur dioxide + water = sulfurous acid
- moist calcium carbonate + sulfurous acid = calcium sulfite + carbon dioxide + water
- calcium sulfite + oxygen = calcium sulfate