5 public questions tagged with this topic.
Acidity of group 15 oxides increases with oxidation state and decreases down the group. N₂O₅ (N in +5) is the most acidic, forming HNO₃, unlike P₂O₅, As₂O₅, or Sb₂O₅.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
Sulfur oxides and nitrogen oxides are atmospheric precursors of acid rain. Sulfur dioxide is oxidised to sulfuric acid, while nitric oxide is converted through nitrogen dioxide and other reactions to nitric acid. These acids dissolve in cloud droplets or deposit as gases and particles. Carbon dioxide creates normal weak rain acidity, whereas methane, sodium chloride, and the other listed pairings do not explain anthropogenic acid deposition. Sound classification links the source, atmospheric fate, exposure route, and mechanism of toxicity rather than relying only on the pollutant's name. Effective management combines cleaner fuels, emission standards, monitoring, urban planning, and protection of populations with high exposure or physiological vulnerability. The distinction is ecologically important because emission control must target either the directly released precursor or the product formed after atmospheric transport and reaction. Exposure depends on concentration, duration, ventilation, weather, and individual susceptibility, so a pollutant's presence alone does not fully predict biological harm.
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology
Sulfur dioxide is a principal precursor of acid rain, especially where sulfur-containing coal and oil are burned. In the atmosphere it is oxidised to sulfuric acid and sulfate, which return through wet or dry deposition. Nitrogen oxides also form nitric acid and contribute significantly, but among the listed single oxides sulfur dioxide is the standard principal association. Sound classification links the source, atmospheric fate, exposure route, and mechanism of toxicity rather than relying only on the pollutant's name. Effective management combines cleaner fuels, emission standards, monitoring, urban planning, and protection of populations with high exposure or physiological vulnerability. The distinction is ecologically important because emission control must target either the directly released precursor or the product formed after atmospheric transport and reaction. Exposure depends on concentration, duration, ventilation, weather, and individual susceptibility, so a pollutant's presence alone does not fully predict biological harm. Atmospheric inversions can trap contaminants near the surface, while wind, turbulence, precipitation, and chemical transformation determine their eventual distribution and removal.
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology
Los Angeles-type smog is oxidising photochemical smog, and ground-level ozone is one of its major components. Strong sunlight drives reactions among nitrogen oxides and volatile organic compounds emitted chiefly by traffic and industry. Sulfur dioxide is more characteristic of traditional coal-smoke or London smog, whereas carbon monoxide may be present but does not define this smog type. The distinction is ecologically important because emission control must target either the directly released precursor or the product formed after atmospheric transport and reaction. Exposure depends on concentration, duration, ventilation, weather, and individual susceptibility, so a pollutant's presence alone does not fully predict biological harm. Atmospheric inversions can trap contaminants near the surface, while wind, turbulence, precipitation, and chemical transformation determine their eventual distribution and removal. At organismal level, respiratory surfaces are especially exposed because large volumes of air contact thin, moist epithelia designed for rapid gas exchange. Sound classification links the source, atmospheric fate, exposure route, and mechanism of toxicity rather than relying only on the pollutant's name.
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology
Photochemical smog develops when volatile organic compounds react through radical chemistry with nitrogen oxides in sunlight. Nitrogen dioxide photolysis releases oxygen atoms that form ozone, while reactions involving VOC-derived peroxy radicals regenerate nitrogen dioxide without consuming ozone. The resulting mixture includes ozone, aldehydes, and peroxyacyl nitrates rather than being a simple accumulation of primary emissions. Effective management combines cleaner fuels, emission standards, monitoring, urban planning, and protection of populations with high exposure or physiological vulnerability. The distinction is ecologically important because emission control must target either the directly released precursor or the product formed after atmospheric transport and reaction. Exposure depends on concentration, duration, ventilation, weather, and individual susceptibility, so a pollutant's presence alone does not fully predict biological harm. Atmospheric inversions can trap contaminants near the surface, while wind, turbulence, precipitation, and chemical transformation determine their eventual distribution and removal. At organismal level, respiratory surfaces are especially exposed because large volumes of air contact thin, moist epithelia designed for rapid gas exchange.
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology
