Hi,
anyone can explain the difference ?
anyone can explain the difference ?
Organic/Anorganic
Organic chemistry is usually about organic compounds, which are hydrocarbons and friends. There are alkanes, alkenes, benzenes, polymers, amides, acyl acids, alcohols, aldehydes, ketones, amino acids... In organic chemistry we learn how to tell those substances apart, their properties, how to make them, how they are important in our life etc. Every living being is made of organic compounds, as well as most medicines.
Inorganic chemistry, on the other hand, is essentially anything not organic, which are mainly about chemical reactions (stoichiometry, bases-acids-salts, buffer solution, rate of reaction, etc), energetics (enthalpy change, exothermic/endothermic process, etc), electrochemistry (how chemical substances create electricity), and chemical properties of elements and compounds (atom radii, reactivity, electronegativity, solubility, etc).
Inorganic chemistry, on the other hand, is essentially anything not organic, which are mainly about chemical reactions (stoichiometry, bases-acids-salts, buffer solution, rate of reaction, etc), energetics (enthalpy change, exothermic/endothermic process, etc), electrochemistry (how chemical substances create electricity), and chemical properties of elements and compounds (atom radii, reactivity, electronegativity, solubility, etc).
I'm not sure there is a clear distinction between organic and an(in)organic.
Typical definitions for organic compounds include;
Containing carbon (but then diamond and graphite are not considered organic)
Containing carbon and oxygen (but CO2 is not normally considered organic)
Containing Carbon and hydrogen (hydrocarbons).
There is no simple answer - basically organic chemistry is concerned with compounds that include carbon combined with one or more of the lighter elements.
PS - See Gagnar's posting below for a much better and more complete explanation.
Last edited by Bikerman on Wed Jan 23, 2008 7:48 pm; edited 1 time in total
Typical definitions for organic compounds include;
Containing carbon (but then diamond and graphite are not considered organic)
Containing carbon and oxygen (but CO2 is not normally considered organic)
Containing Carbon and hydrogen (hydrocarbons).
There is no simple answer - basically organic chemistry is concerned with compounds that include carbon combined with one or more of the lighter elements.
PS - See Gagnar's posting below for a much better and more complete explanation.
Last edited by Bikerman on Wed Jan 23, 2008 7:48 pm; edited 1 time in total
Organic chemistry also tends to consider only those elements that are present in biological compounds. The big four are:
carbon
oxygen
hydrogen
nitrogen
Next come things like
sulphur
chlorine
fluorine
bromine
sodium
potassium
calcium
phosphorous
silicon
And a few other metals
iron
magnesium
manganese
zinc
copper
And sometimes things like lead, nickel, mercury and silver, which are noteworthy for NOT belonging in living systems and which tend to inactivate or precipitate organic compounds. The focal molecules of organic chemistry tend to be hydrocarbons (carbon chains with a lot of attached hydrogens and sometimes other things), carbohydrates (molecules containing roughly as many oxygens as carbons and as many hydrogens as both carbons and oxygens and with all the carbons in a backbone), and nitrogenous compounds that are like carbohydrates with nitrogens added to the backbone. Organic molecules can get big and complex, but they all have forms based on these three types (and a few others). Even though the description seems fuzzy, it's pretty easy to look at a molecular structure and say immediately whether the molecule would be classified as 'organic.'
Organic chemists research these types of molecules because they are important in biological systems, and because they happen to have many other uses as well. Nature selected those molecules because they are incredibly diverse in their properties. Minor changes in composition and sequence of atoms causes major changes to the properties. Things like reactivity, volitility, solubility, melting point, viscosity and charge are all highly variable. Metal-containing organic compounds often react with light and make dyes and pigments. Plastics, oils, preservatives, medicines, poisons, solvents, and adhesives are all almost entirely composed of 'organic' compounds.
carbon
oxygen
hydrogen
nitrogen
Next come things like
sulphur
chlorine
fluorine
bromine
sodium
potassium
calcium
phosphorous
silicon
And a few other metals
iron
magnesium
manganese
zinc
copper
And sometimes things like lead, nickel, mercury and silver, which are noteworthy for NOT belonging in living systems and which tend to inactivate or precipitate organic compounds. The focal molecules of organic chemistry tend to be hydrocarbons (carbon chains with a lot of attached hydrogens and sometimes other things), carbohydrates (molecules containing roughly as many oxygens as carbons and as many hydrogens as both carbons and oxygens and with all the carbons in a backbone), and nitrogenous compounds that are like carbohydrates with nitrogens added to the backbone. Organic molecules can get big and complex, but they all have forms based on these three types (and a few others). Even though the description seems fuzzy, it's pretty easy to look at a molecular structure and say immediately whether the molecule would be classified as 'organic.'
Organic chemists research these types of molecules because they are important in biological systems, and because they happen to have many other uses as well. Nature selected those molecules because they are incredibly diverse in their properties. Minor changes in composition and sequence of atoms causes major changes to the properties. Things like reactivity, volitility, solubility, melting point, viscosity and charge are all highly variable. Metal-containing organic compounds often react with light and make dyes and pigments. Plastics, oils, preservatives, medicines, poisons, solvents, and adhesives are all almost entirely composed of 'organic' compounds.
To me the difference is a matter of acquaintance: when you've worked with both, you just know whether a subject or substance is organic or inorganic. As Gagnar puts it:
And of course you can describe in general what elements organic substances usually have etc. but I don't see the point in that. It will still be fuzzy to outsiders. You're either into chemistry (and then you can apply it, i.e. do some fine organic synthesis) or you're not. In the first case you will know the difference regardless of your field, in the second case it's really no use knowing. (Except maybe for scoring points on national television quiz shows.)
So I was just wondering... why are you asking this?
| Quote: |
| Even though the description seems fuzzy, it's pretty easy to look at a molecular structure and say immediately whether the molecule would be classified as 'organic.' |
So I was just wondering... why are you asking this?
Struggling to remember my CSYS Chemistry (roughly A level) organic compounds are ususally long chain hydrocarbon molecules. I think beyond that there is much overlap and a defintion is probably easier based on examples rather than a strict set of rules.
According to wikipedia (sorry) the name came from the mistaken belief that organic compounds were always related to life processes, so that might get you the points on a TV quiz show.
According to wikipedia (sorry) the name came from the mistaken belief that organic compounds were always related to life processes, so that might get you the points on a TV quiz show.
Well, supposing that it is true that the first living things were formed from random collections of molecules, which were in turn randomly assembled... If that is the case, then there really is no distinction, because organic materials are just a complex collections of inorganic substances.
| ocalhoun wrote: |
| Well, supposing that it is true that the first living things were formed from random collections of molecules, which were in turn randomly assembled... If that is the case, then there really is no distinction, because organic materials are just a complex collections of inorganic substances. |
^Well, what I meant was that some carbon, oxygen, hydrogen, et cetera randomly combining. If inorganic chemicals can become organic, then what is the difference between the two.
I think there is some confusion about nomenclature. The fact that we call the chemicals 'organic' doesn't mean that they are special or alive or naturally formed. It just means that they are contain carbon-hydrogen bonds. The reason for the name is that organic compounds were only really found in living beings when they were first characterized.
Not all chemicals in living organisms are organic, and organic chemicals do occur outside of living organisms.
Formation of organic compounds is energy-intensive because carbon is at a much lower energy state when bound to oxygen than when bound to hydrogen. That's why I think organic compounds are mostly unique to living beings and not often synthesized abiotically. If you think about it oils don't just exude from rocks, so the abundance of organic compounds on Earth is something special that can only happen when life is around.
The reason we keep the distinction between organic and inorganic compounds is that the chemistry involving organic compounds is sort of unique and limited to organic compounds. Organic chemists think about reactions that simply don't occur with inorganic compounds, and don't worry about reactions that don't occur with organic compounds. They use different tools and techniques than inorganic chemists because the molecules they study are pretty unique.
Not all chemicals in living organisms are organic, and organic chemicals do occur outside of living organisms.
Formation of organic compounds is energy-intensive because carbon is at a much lower energy state when bound to oxygen than when bound to hydrogen. That's why I think organic compounds are mostly unique to living beings and not often synthesized abiotically. If you think about it oils don't just exude from rocks, so the abundance of organic compounds on Earth is something special that can only happen when life is around.
The reason we keep the distinction between organic and inorganic compounds is that the chemistry involving organic compounds is sort of unique and limited to organic compounds. Organic chemists think about reactions that simply don't occur with inorganic compounds, and don't worry about reactions that don't occur with organic compounds. They use different tools and techniques than inorganic chemists because the molecules they study are pretty unique.
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