Chemistry in Action

QUESTION 1:
For the dissolved oxygen reactions:
What type of reaction is 1a? double replacement
What type of reaction is 1b? synthesis
What do you think reaction 2 and 3 are? triple replacement
QUESTION 2:
a. What is hypoxia?
Hypoxia is when the oxygen concentration in water is below the levels necessary for sustainable life.
b. When does hypoxia reach its highest levels in Long Island Sound and in the Gulf of Mexico?
Hypoxia is at its highest in the Long Island Sound from mid-July to September. It is the same for the Gulf of Mexico.
c. What are the causes of hypoxia?
One cause of hypoxia is that fresh water and salt water interact, particularly at the Gulf of Mexico. Another is an increase in nitrogen and phosphorus use by humans.
d. Research the sources of high levels of nitrate ion in water bodies.
Nitrates get into water because of the increase in human use. People use nitrates in their fertilizer, and there is runoff, which ends up in the ocean. Human and animal waste can also contribute to the nitrate levels in water.
e. 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?
According to the EPA, the Maximum Contaminant Level of nitrate is 10 ppm. It can cause blood disorders in infants, called “blue baby syndrome.” If pregnant women drink it, it can cause defects in their babies. It can also increase the risk of cancer.
http://toxics.usgs.gov/definitions/hypoxia.html
http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listByNewest&r=231335&subtop=274
http://www.bfhd.wa.gov/info/nitrate-nitrite.php http://www.dnr.state.wi.us/org/water/dwg/nitrate.htm