Question

Name two different chemicals we have discussed or read about that we have added to the carbon cycle at levels that did not exist naturally.

a. Which functional group class does each chemical belong to? Explain.

b. How do the respective types of bonding and functional group classes of these molecules affect their reactivity?

c. What are the health and environmental effects of the two chemicals you choose to report on? Make sure to obtain your information from reliable sources such as your textbook and reference relevant sources.

d. Take one of the chemicals you choose to discuss and explain the properties of that chemical (such as water solubility, vapor pressure, etc.) that determines its migration in our environment. Search for the octanol/water solubility constant, provide that value and explain in a single sentence what this information tells us about that compound.

e. Name one green chemistry principle that could have the greatest potential to minimize the future impact of each of the two chemicals you discussed, explaining how each green chemistry principle can be applied specifically to each chemical.

Answer 1

The first one is the chlorofluorocarbons and the second is halons that we have added it to the carbon cycle and still are adding to.

a) chlorofluorocarbons may have have some types like CFC-11 ,CFC-12, CFC-113 . they have the molecular formula as CCl₂F₂ (CFC-12) , C₂Cl₂F₃(CFC-113) means belongs with halogen group.  

Halons are fluorocarbons with atleast one bromine atom , have the molecular formula CF₂ClBr(halon1211).

b) As in simplar alkanes,carbon in CFCs and the HCFCs is tetrahedral.The physical properties are tunable by changes in the number and the identity of the halogen atoms . In general,they are volatile but less than so their parent alkanes.The densities are higher than the corresponding alkanes.

c) since the late 1970s,the use of CFCs and other alike has been heavily regulated because of their destructive effects on the ozone layer. This anthropogenic compound is also a greenhouse gas,with a much higher potential to enhance the green house effect than CO2.Overexposure at concentrations of 11% or more may cause dizziness, loss of concentraton , central nervous systemn depression and/ or cardiac arrhythmia.

d) The solubility measurements of CFCs have been previously measured by Warner ad Weiss.from datas it can be noted, that the solubility of CFCs are increases with decreasing temperature at approximately 1% per degree celsius.

e) Hydrofluorocarbons are included in the kyotoprotocol because of their very high global warming potential and are facing calls to be regulated under the montreal protocal due to the recognition of halocarbon contributions to climate change.