1. Alcohols And Phenols

Alcohols contain a hydroxyl ($\text{-OH}$) group attached to a saturated carbon atom, with the general formula $\text{R-OH}$. Phenols have a hydroxyl group directly attached to an aromatic ring. Both exhibit hydrogen bonding, influencing their physical properties like higher boiling points compared to corresponding alkanes. Ethanol ($\text{C}_2\text{H}_5\text{OH}$) is a common alcohol used as a solvent and in beverages, while phenol ($\text{C}_6\text{H}_5\text{OH}$) is used in disinfectants and the synthesis of plastics like Bakelite.

2. Ethers

Ethers have the general formula $\text{R-O-R'}$, where R and R' are alkyl or aryl groups. They are relatively unreactive compounds, primarily used as solvents due to their ability to dissolve many organic substances. Diethyl ether ($\text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3$) is a common example, historically used as an anesthetic. Ethers can be prepared by the Williamson ether synthesis, involving the reaction of an alkoxide with an alkyl halide.

3. Aldehydes And Ketones (Introduction & Properties)

Aldehydes ($\text{RCHO}$) and ketones ($\text{R-CO-R'}$) both contain a carbonyl group ($\text{C=O}$). In aldehydes, the carbonyl carbon is attached to at least one hydrogen atom, while in ketones, it is attached to two carbon atoms. These compounds exhibit characteristic physical properties influenced by the polarity of the carbonyl group, though they generally have lower boiling points than alcohols due to the absence of hydrogen bonding between carbonyl molecules. Methanal ($\text{HCHO}$) and ethanal ($\text{CH}_3\text{CHO}$) are simple aldehydes.

4. Aldehydes And Ketones (Chemical Reactions)

The carbonyl group makes aldehydes and ketones reactive, primarily undergoing nucleophilic addition reactions. The carbonyl carbon is electrophilic due to the polar $\text{C=O}$ bond. Aldehydes are generally more reactive than ketones because the carbonyl carbon in aldehydes is less sterically hindered and benefits from electron-donating effects from alkyl groups being less pronounced compared to ketones. Reactions include addition of Grignard reagents, HCN, and reduction to alcohols.

5. Carboxylic Acids (Introduction & Preparation)

Carboxylic acids ($\text{R-COOH}$) contain a carboxyl group, characterized by a carbonyl group attached to a hydroxyl group. They are acidic due to the ability of the carboxyl group to donate a proton. Common preparation methods include the oxidation of primary alcohols and aldehydes, and hydrolysis of nitriles and esters. Acetic acid ($\text{CH}_3\text{COOH}$), the main component of vinegar, is a simple carboxylic acid widely used in food preservation and industrial applications.

6. Carboxylic Acids (Physical And Chemical Properties)

Carboxylic acids exhibit strong hydrogen bonding, leading to higher boiling points and melting points compared to alcohols of similar molecular weight. They are soluble in water due to the polar carboxyl group. Chemically, they undergo reactions typical of their functional group, including reactions with metals to produce hydrogen gas, reaction with bases to form salts, esterification with alcohols, and reactions involving the carboxyl group itself, such as decarboxylation. Their acidity is a key chemical property.