Organic Chemistry is the study of what

[Precursor]

Homework Statement

Modern organic chemistry is the study of:

a) only molecular compounds
b) only petrochemicals
c) only natural molecules
d) molecules of carbon

The Attempt at a Solution

I think the answer is c) because organic chemistry looks at molecules of (dead) plants, animals and fossil fuels, to name a few. All of these are natural compounds. I know that a) is not the answer, because not all molecular compounds are studied. I also doubt the answer is b), because petrochemicals only come from petroleum, which is not the only focus in organic chemistry. However, I am not sure whether the answer could be d). Any help would be appreciated.

 

[mgb_phys]

"Organic chemistry is a discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds that contain carbon."

 

[Precursor]

"Organic chemistry is a discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds that contain carbon."

So my first answer is not correct because organic chemistry is also the study of synthetic or man-made chemical compunds? I had thought that organic compounds were strictly naturally occurring molecules. Could someone please clarify this?

 

[mgb_phys]

Organic chemistry is the study of carbon compounds ( generally C-H,C-O bonds) the organic is a bit of a historical accident. It was originally thought that living things had some fundamental different substance to non-living things but ironically organic chemistry really became a science when somebody created a chemical previously only found in nature in the lab

 

[Borek]

Nanoputians - being organic - are not naturally occurring.

 

[bromonium]

Organic chemistry is the study of carbon compounds, specifically those containing C–C and C–H bonds. mgb_phys said that these include C–O bonds but strictly speaking this is not the case; many organic molecules do include heteroatoms (atoms other than C or H) but to qualify as an organic molecule a species must contain at least one C–C or C–H bond. For this reason CO₂ (carbon dioxide) and CO (carbon monoxide) are not considered organic compounds. The simplest organic compounds are the hydrocarbons, molecules which contain only carbon and hydrogen atoms, but many organic compounds contain other elements. The most common heteroatoms in organic chemistry are N, O, F, Cl, Br, I, S, and P.

As mgb_phys also pointed out, the confusion over the definition of "organic" stems from the history of science and philosophy. It was long believed that living organisms contained a vital force (this view is called vitalism) and that organic compounds could not be synthesized from inorganic starting materials. Chemists eventually found that this is not the case and that biological systems are subject to the same chemistry as abiotic systems. Most biological molecules are organic and organic material comprises the bulk of most living things. Proteins, carbohydrates, fats and DNA, for example, are all organic molecules.

 

[mgb_phys]

For this reason CO2 (carbon dioxide) and CO (carbon monoxide) are not considered organic compounds.

What about CCl4 ? - It's a VOC according to the EPA

 

[Borek]

Is sodium oxalate organic?

 

[bromonium]

Sodium oxalate is definitely organic because the oxalate ion contains a C–C bond (see http://en.wikipedia.org/wiki/File:Sodium-oxalate-2D.png" ). Although CCl₄ does not contain any C–C or C–H bonds, I suppose the rationale for labeling it an organic is that it could be considered a tetra-substituted methane, hence its IUPAC name, tetrachloromethane. Perhaps I was a little hasty in giving my definition of organic compounds, but I maintain that possession of the C–O is not sufficient for a compound to be considered organic. Presumably this distinction is also historical—carbonates, carbon oxides, diamond and graphite were studied by inorganic chemists and geologists while carbohydrates and lipids were studied by organic chemists, biochemists and biologists before more was known about their structure at the atomic and molecular levels. Of course these distinctions are fairly arbitrary. -C≡N can be named as an inorganic salt or as an organic functional group: NaCN is sodium cyanide but CH₃CH₂CN is propanenitrile.

See: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch10/carbon.php" .

 

[Borek]

Yep, you got me with oxalic acid. But urea - first organic compound to be synthesized - doesn't contain any C-C nor C-H bonds (so is not organic ).

Distinction is mostly historical - and as such doesn't have to make much sense.

I would not pay special attention to the definition. No matter what definition you try to apply there will be some border cases. For me trying to classify every compound as either organic or inorganic is a waste of time.

 

[bromonium]

Perhaps the most important point is that these definitions are both historical and arbitrary, and urea provides an excellent example of this. It was first isolated and characterized in living systems and because it contains functional groups that are common in organic chemistry it remains an appropriate topic of modern research and education in organic chemistry. Another interesting example is that of the http://en.wikipedia.org/wiki/Fullerene_chemistry" , which are considered a topic of organic chemistry while other carbon allotropes such like graphite and diamond are not. The historical connections are also relevant here; fullerene chemistry employs classic techniques of organic synthesis while carbon-based minerals have traditionally been studied by chemists and other scientists outside of organic chemistry.

The quickie definition I usually give people who ask me is that organic compounds contain a "carbon backbone" or "carbon skeleton." This doesn't explicitly exclude carbonates et al and so is probably no better than defining it simply as carbon chemistry, for simplicity's sake.

 

[Precursor]

So modern organic chemistry is the study of carbon molecules, excluding oxides and ionic compounds of carbon-based ions such as carbonate, cyanide, and carbide ions. A historical perspective of organic chemistry was one based on the belief that organic molecules were naturally occurring, or were derived from living entities. I think I got now. Thanks for the help guys.