Physical Properties of Alcohol: Hydrogen Bonding, Solubility, and Boiling Point February 4, 2018 By Leah4sci Leave a Comment The key to understanding physical properties of alcohol, including hydrogen bonding solubility and boiling point is to understand the structure and charge distribution within the alcohol functional group. Alcohols. An alcohol is an organic compound with a hydroxyl (OH) functional group on an aliphatic carbon atom. This is due to the presence of intermolecular hydrogen bonding between hydroxyl groups of alcohol molecules. Some prominent physical and chemical properties of alcohols are given below. The first one has the alkyl group and the other has the hydroxyl group. Alcohol molecules all contain the hydroxyl (-OH) functional group. ; The carbon attached to OH define if an alcohol is “primary”, “secondary”, or “tertiary”. The alcohols are a homologous series. However, phenol is sufficiently acidic for it to have recognizably acidic properties - even if it is still a very weak acid. Compounds like alcohols and phenol which contain an -OH group attached to a hydrocarbon are very weak acids. They are a homologous series and have the general formula C n H 2n + 1 OH. They are: This is due to the hydroxyl group in the alcohol which is able to form hydrogen bons with water molecules. The alcohol functional group: Alcohols are characterized by the presence of an -OH group, which is generally in a bent shape, like that of water. Nomenclature. Alcohols are soluble in water. Alcohols contain the hydroxy functional group (-OH), bonded to a carbon atom of an alkyl or substituted alkyl group. The properties of hydrocarbon derivatives are determined largely by the functional group. The –OH group is the functional group of an alcohol. Most of the common alcohols are colourless liquids at room temperature. A hydrocarbon derivative can be formed by replacing one or more hydrogen atoms of a hydrocarbon by a functional group, which contains at least one atom of an element other than carbon or hydrogen. Examples: Physical properties of alcohols. Methyl alcohol, ethyl alcohol, and isopropyl alcohol are free-flowing liquids with fruity odours. Functional Groups are the substituent atoms or group of atoms that attach to a molecule and enable them to participate in specific chemical reactions. Alcohols are so weakly acidic that, for normal lab purposes, their acidity can be virtually ignored. The Boiling Point of Alcohols. The higher alcohols—those containing 4 to 10 carbon atoms—are somewhat viscous, or oily, and they have heavier fruity odours. Some of the highly branched alcohols and many alcohols containing more than 12 … of organic compounds. Chapter 3 Alcohols, Phenols, and Ethers 2 3 Alcohols 4 The Hydroxy (—OH) Functional Group •The hydroxyl group (—OH) is found in the alcohol and phenol functional groups. 2. chemical compounds that contain both an amine -NH2 functional group and a carboxylic acid -COOH functional group 3. complex molecules constructed from long chains of amino acids polymerized together 4. the linking of smaller molecules to form long chain molecules of high molecular weight Alcohols with a smaller hydrocarbon chain are very soluble. The functional group of an alcohol is the hydroxyl group, –OH. Functional groups include hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl. (Note: that’s not the same as hydroxide, OH-, which is ionic.) When naming alcohols, the -e is removed from the hydrocarbon name and an -ol suffix is added. Functional groups, including alcohol hydroxyl group, phenolic hydroxyl group, carbonyl group, carboxyl group, methoxyl, and sulfonic acid, are important structural characteristics of lignin. Alcohol - Alcohol - Reactions of alcohols: Because alcohols are easily synthesized and easily transformed into other compounds, they serve as important intermediates in organic synthesis. The alcohol functional group hydroxyl is an -OH group. They all contain the functional group –OH , which is responsible for the properties of alcohols. The chart shows the boiling points of some simple primary alcohols with up to 4 carbon atoms. –in phenols, —OH is connected to a benzene ring. Boiling Points. Alcohols are organic compounds where a hydroxyl group replaces the hydrogen atom of an aliphatic carbon. Key Facts & Summary. –in alcohols, a hydroxyl group is connected to a carbon atom. Alcohols are the family of compounds that contain one or more hydroxyl (-OH) groups attached to a single bonded alkane. Not all functional groups containing OH are alcohols. As the length of the hydrocarbon chain increases, the solubility in water decreases. Physical Properties of Alcohol. Physical properties of alcohols. In a tertiary (3°) alcohol, the carbon atom holding the -OH group is attached directly to three alkyl groups, which may be any combination of same or different. Tertiary alcohols. It is used as a local anesthetic and to reduce pain associated with Lidocaine injection. Their names all end in -ol. A multistep synthesis may use Grignard-like reactions to form an alcohol with the desired carbon structure, followed by reactions to convert the hydroxyl group of the alcohol to the desired functionality.