Different Types of Alcohol
Types of alcohol uses for the manufacture of beer, wine, brandy is ethanol but alcohols like monohydric, polyhydric, aromatic, and aliphatic alcohol uses in different alcoholic beverages and drug preparation. Alcohol is the organic compounds or hydroxyl derivative of hydrocarbon mainly alkane and isomers of ethers prepared on the specific heat with dilute sulphuric acid under pressure. According to the number of functional or alcoholic groups, these organic compounds in chemical science are classified as, Monohydric Dihydric, Trihydric, Polyhydric. The lower members are liquids and lees volatile due to association through hydrogen bonding extending over a chain of molecules but higher members are solid and almost orderless.
The lower alcohols are very soluble in water and solubility diminishes as molecular weight increases because the oxygen atom of the hydroxyl group forms hydrogen bonding with water molecules. Alcohols libate hydrogen atom by the action of metals shows acid properties but they do not affect the pH level of the water solution since they are weaker acid than water. Therefore, the alkoxides beings hydrolyzed by water, and for this reason, ethoxide is the stronger base than hydroxide ion.
Infrared spectrum studies of hydroxyl groups in alcohols show they absorbed electromagnetic radiation with the frequency from 3650 to 3580 cm-1 and this is true only if there is no hydrogen bonding. Therefore, intermolecular hydrogen bonding produces absorption in the region from 3550 to 3230 cm-1.
Monohydric and Polyhydric Alcohol in Chemistry
Monohydric alcohols contain one alcoholic group and dihydric and trihydric contain two or three alcoholic groups. But the alcohols contain four or more than four alcoholic groups called polyhydric alcohols. The monohydric alcohols are the simplest with the general molecular formula, CnH2n+2O or CnH2n+1OH.
Aromatic and Aliphatic alcohol
But other types of classification of alcohol given according to the attached alcoholic group to the aromatic or aliphatic Hydrocarbon. Hence these alcohol names as aliphatic and aromatic alcohols.
- Aliphatic alcohols are compounds containing hydroxyl groups in the side chain of the alkyl group. Thus these types are the alkyl derivative of alcohol.
- Aromatic alcohols are compounds containing alcoholic groups directly attached to the nucleus of the benzene ring. Hence these types are known as the aryl derivative of alcohol.
Types of aliphatic alcohol
- Methanol, ethanol, propanol, butanol, isobutanol, etc are examples of monohydric alcohols because these contain only one hydroxyl group.
- But ethylene glycol, trimethylene glycol, pentamethylene glycol, isobutene glycol are dihydric types of aliphatic alcohols because these contain two alcoholic groups.
- The only important trihydric aliphatic organic compound is glycerol or propane-1-2-2-triol because these contain three alcoholic groups. Glycerol occurs in almost all animals and vegetable oils.
- Hence D-sorbitol, D-mannitol, and dulcitol are the polyhydric aliphatic alcohols that occur naturally contain more than three hydroxyl groups.
Types of Aromatic Alcohol
Aromatic alcohols are also classified as monohydric, dihydric, trihydric, and polyhydric phenols, according to the hydroxyl group attached to the benzene ring. Therefore, phenol, catechol (o-dihydroxybenzene), Resorcinol (m-dihydroxybenzene)quinol (p-dihydroxy benzene ) are examples of these types of alcohols.
Monohydric Alcohol Formula
Monohydric alcohols are further classified according to formula as primary, secondary, and tertiary alcohol. Hence This classification based on the position of the alcoholic group attached to the alkyl. If the alcoholic group attached to the alpha, beta, and gamma carbon atom, then these alcohols are known as primary secondary and tertiary respectively.
Chemical Names and Formula of Alcohol
Different types of simpler monohydric alcohols are known by their trivial names for learning chemistry. This type of naming obtained from alcohol formula which is the chemical derivative of the alkenes like methane, ethane, propane, etc attached to the hydroxyl or alcoholic group.
But other types of naming by considering the alcohols as the derivative of methanol. For example, CH3CH2CH3OH, eathy methanol, and CH3CH2CH(OH)CH3, methyl ethyl methanol.
Common Uses of Alcohol
Alcohols are the commercially essential organic compounds and common types of alcohol use in alcoholic beverages like wine and beer and the chemical industry.
- Hence it used as a solvent for paints, varnishes, shellac, celluloid, and cement plant.
- When ethanol mixed with small amounts of methanol forms methylated spirit. This mixture used as an automobile antifreeze mixture, remove ink from various kind of surface.
- Alcohols used for manufacturing dyes and drugs, perfumes, etc, and ethanol also used as an alternate fuel of the motor vehicle.
- Common alcohol like Phenol, methanol, ethanol uses as an antiseptic and sanitizer. It also uses for the preparation of drugs and bakelite.
Preparation of Alcohol by Fermentation
Fermentation in the environment is the earliest process for the preparation of ethyl alcohol by the catalyst. But this process still uses for the manufacture of beer, wine, and brandy. The common materials used for these chemical reactions are wheat, barley, or potato. Hence the mashed materials boiling at 50°C for one hour. But the melt contains the enzyme diastase, which converted starch into maltose and sugar by hydrolysis.
2(C6H10O5)n + nH2O → nC12H22O11
The liquid is cooled to 300°C and fermented with yeast for 1-3 days. But yeast contains various enzymes, among which maltase converts maltose into glucose and zymase. But zymase further converted glucose into ethanol.
C12H22O11 + H2O → 2C6H12O6
C6H12O6 → 2C2H5OH + 2CO2