Julia Hyland April 1, 2011
Chemistry Block 7
What type of reaction is 1a?: Double replacement
What type of reaction is 1b?: Synthesis
What do you think reaction 2 and 3 are?: Neutralization
1. What is hypoxia
The term "hypoxia" means low dissolved oxygen ("DO") concentrations in the water. Marine organisms need oxygen to live, and low concentrations, depending on the duration and the size of the area affected, can have serious consequences for a marine ecosystem.
2. When does hypoxia reach its highest levels in the Long Island Sound and in the Gulf of Mexico?
Hypoxia reaches its highest levels in the Long Island Sound and in the Gulf of Mexico during the summer. This is primarily because there are calm weather conditions throughout the summer, which prevents the mixing of the water column that replenishes bottom water oxygen during the rest of the year. Studies also show that summer oxygen depletion in Western Long Island Sound has grown worse since the late 1950s.
3. What are the causes of hypoxia?
Some of the main causes of hypoxia include temperature, salinity, vegetation and bacteria.
4. Research the sources of high levels of nitrate ion in water bodies.
Many bodies of freshwater are currently experiencing high levels of nitrogen and phosphorus from fertilizer containing nitrates and in some cases particular agricultural practices and animal waste. The increase in levels of nitrogen in bodies of water is leading to an increase of algae and other aquatic plants in the water.
5. What are “safe levels” of nitrate in drinking water and what are the effects on humans of drinking water with high levels of nitrate ion?
High nitrate levels in water can cause blue baby syndrome, which is a condition found especially in infants under six months. The stomach acid of an infant is not as strong compared to older children and adults, which causes an increase in bacteria that can readily convert to nitrate. High levels on nitrates in drinking water can also cause hypoxia in humans, where there is a reduced oxygen supply to vital parts of the body, such as the brain. The U.S. Environmental Protection Agency has declared that 10 mg/l of nitrate is a “safe level” for drinking water.
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