- (E) When atmospheric water reacts with sulfur and nitrogen compounds
that result from industrial processes, the result can be the formation of
sulfuric (H 2 SO 4 ) and nitric (HNO 3 ) acid in rainwater. However, the amount
of acidity that is deposited in rainwater is much less, on average, than that
created through agricultural activities. Acid soils are most often found in
areas of high rainfall. Additionally, rainwater has a slightly acidic pH of 5.7
due to a reaction with CO 2 in the atmosphere that forms carbonic acid.
Ammonium (NH 4 +) fertilizers react in the soil in a process called
nitrification to form nitrate (NO 3 – ), and, in the process, they release H+ ions.
Highly weathered soils are often characterized by high concentrations of Fe
and Al oxides. Severely acidic conditions can form in soils near mine spoils
due to the oxidation of pyrite also known as iron sulfide (FeS 2 ). In addition
to the choices listed, potential acid sulfate soils naturally formed in
waterlogged coastal and estuarine environments can become highly acidic
when drained or excavated, and decomposition of organic matter by
microorganisms can release carbon dioxide (CO 2 ), which can form carbonic
acid (H 2 CO 3 ) when mixed with soil water.
marvins-underground-k-12
(Marvins-Underground-K-12)
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