Class 11 Functional Groups

Cheatsheet Content

1. Hydrocarbons Alkanes General Formula: $C_nH_{2n+2}$ Functional Group: C-C single bonds (saturated) Example: Ethane ($CH_3-CH_3$) Alkenes General Formula: $C_nH_{2n}$ Functional Group: C=C double bond Example: Ethene ($CH_2=CH_2$) Alkynes General Formula: $C_nH_{2n-2}$ Functional Group: $C \equiv C$ triple bond Example: Ethyne ($CH \equiv CH$) Aromatic Hydrocarbons (Arenes) Functional Group: Benzene ring (conjugated double bonds) Example: Benzene ($C_6H_6$) 2. Halogen Derivatives Haloalkanes (Alkyl Halides) General Formula: $R-X$ (where $X = F, Cl, Br, I$) Functional Group: Halogen atom ($X$) bonded to an alkyl group ($R$) Example: Chloromethane ($CH_3-Cl$) 3. Oxygen-Containing Functional Groups Alcohols General Formula: $R-OH$ Functional Group: Hydroxyl group ($-OH$) Example: Ethanol ($CH_3CH_2-OH$) Ethers General Formula: $R-O-R'$ Functional Group: Ether linkage ($-O-$) between two alkyl or aryl groups Example: Dimethyl ether ($CH_3-O-CH_3$) Aldehydes General Formula: $R-CHO$ Functional Group: Aldehyde group ($-CHO$) O // R-C-H Example: Ethanal ($CH_3-CHO$) Ketones General Formula: $R-CO-R'$ Functional Group: Ketone group ($-CO-$) O // R-C-R' Example: Propanone ($CH_3-CO-CH_3$) Carboxylic Acids General Formula: $R-COOH$ Functional Group: Carboxyl group ($-COOH$) O // R-C-OH Example: Ethanoic acid ($CH_3-COOH$) Esters General Formula: $R-COOR'$ Functional Group: Ester group ($-COO-$) O // R-C-OR' Example: Methyl ethanoate ($CH_3-COO-CH_3$) 4. Nitrogen-Containing Functional Groups Amines General Formula: $R-NH_2$ (primary), $R_2NH$ (secondary), $R_3N$ (tertiary) Functional Group: Amino group ($-NH_2$, $-NHR$, $-NR_2$) Example: Methylamine ($CH_3-NH_2$) Nitriles (Cyanides) General Formula: $R-C \equiv N$ Functional Group: Cyano group ($-C \equiv N$) Example: Ethanenitrile ($CH_3-C \equiv N$) Nitro Compounds General Formula: $R-NO_2$ Functional Group: Nitro group ($-NO_2$) Example: Nitromethane ($CH_3-NO_2$) 5. Sulfur-Containing Functional Groups Thiols (Mercaptans) General Formula: $R-SH$ Functional Group: Sulfhydryl group ($-SH$) Example: Ethanethiol ($CH_3CH_2-SH$)