Greetings,
This post discusses functional groups and specifically alcohols.
A functional group is a cluster of two or more covalently bonded atoms, which when added to a hydrocarbon molecule, results in another compound. Examples of compounds which can be formed are ethers, esters, amines, aldehydes, ketones, carboxylic acids, and alcohols.
Alcohols are formed by the addition of a hydroxyl group, -OH, to a hydrocarbon. Actually, strictly speaking, the hydroxyl group is not added but rather substituted in place of a hydrocarbon hydrogen atom. Here's an example:
CH4 is the hydrocarbon, Methane. Let's rewrite the methane formula and then "bring in" a hydroxyl group.
CH4 = CH3H, CH3H + OH --> CH3OH + H
We've just formed methyl alcohol, also known as methanol! While the net addition of a single oxygen atom does not look like much of a change, it makes a huge difference in terms of properties, such as state at room temperature, water solubility, and density, just to name a few.
Where do we encounter alcohols in our daily lives? The answer is everywhere! Ethyl alcohol is added to gasoline and is also the active ingredient of our "favorite adult beverage". Ethyl alcohol is also used in hand sanitizing lotions. Methyl alcohol is used to power formula-one race cars. Isopropyl alcohol is the active part of rubbing alcohol. Sterno portable burners are made with ethanol and a small amount of methanol to denature (make poisonous) the gel material. Oh the things we'll consume to get intoxicated! Then too, there is a federal law which requires all ethanol-containing products to be sold as alcoholic beverages if they are not denatured. Of course, this also means those beverages would require licensing and also would require collection of the federal alcohol tax!
Here is a chart of lowest molecular weight alcohols.
When the carbon chain is three or more carbon atoms long, we must specify the locaton of the hydroxyl group in the name. For these "3 or more carbon chains", we use n- (as in 'normal') in the name. Any alcohols with a single -OH group or hydrocarbon-OH group bonded to the central carbon of a three C-atom chain are "iso-" alcohols. Also, alcohols with -OH at the end or terminal carbon are called primary. If the -OH group is bonded to a carbon atom, which in turn, is bonded to two carbon atoms we have a secondary alcohol, for which "sec-" is used in the name. In a similar fashion, an -OH group bonded to a carbon, in turn bonded to three carbons, is a tertiary alcohol and then we use "tert-" in the name.
That's all for this post. As always, thank you for reading!
A Publication of http://ExcellenceInLearning.biz
This post discusses functional groups and specifically alcohols.
A functional group is a cluster of two or more covalently bonded atoms, which when added to a hydrocarbon molecule, results in another compound. Examples of compounds which can be formed are ethers, esters, amines, aldehydes, ketones, carboxylic acids, and alcohols.
Alcohols are formed by the addition of a hydroxyl group, -OH, to a hydrocarbon. Actually, strictly speaking, the hydroxyl group is not added but rather substituted in place of a hydrocarbon hydrogen atom. Here's an example:
CH4 is the hydrocarbon, Methane. Let's rewrite the methane formula and then "bring in" a hydroxyl group.
CH4 = CH3H, CH3H + OH --> CH3OH + H
We've just formed methyl alcohol, also known as methanol! While the net addition of a single oxygen atom does not look like much of a change, it makes a huge difference in terms of properties, such as state at room temperature, water solubility, and density, just to name a few.
Where do we encounter alcohols in our daily lives? The answer is everywhere! Ethyl alcohol is added to gasoline and is also the active ingredient of our "favorite adult beverage". Ethyl alcohol is also used in hand sanitizing lotions. Methyl alcohol is used to power formula-one race cars. Isopropyl alcohol is the active part of rubbing alcohol. Sterno portable burners are made with ethanol and a small amount of methanol to denature (make poisonous) the gel material. Oh the things we'll consume to get intoxicated! Then too, there is a federal law which requires all ethanol-containing products to be sold as alcoholic beverages if they are not denatured. Of course, this also means those beverages would require licensing and also would require collection of the federal alcohol tax!
Here is a chart of lowest molecular weight alcohols.
When the carbon chain is three or more carbon atoms long, we must specify the locaton of the hydroxyl group in the name. For these "3 or more carbon chains", we use n- (as in 'normal') in the name. Any alcohols with a single -OH group or hydrocarbon-OH group bonded to the central carbon of a three C-atom chain are "iso-" alcohols. Also, alcohols with -OH at the end or terminal carbon are called primary. If the -OH group is bonded to a carbon atom, which in turn, is bonded to two carbon atoms we have a secondary alcohol, for which "sec-" is used in the name. In a similar fashion, an -OH group bonded to a carbon, in turn bonded to three carbons, is a tertiary alcohol and then we use "tert-" in the name.
That's all for this post. As always, thank you for reading!
A Publication of http://ExcellenceInLearning.biz
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