Can You Smell Chemistry Tonight? Quiz

Answer: Geosmin

Geosmin has the chemical formula C12H22O, and its name is derived from the Greek words 'geo', meaning 'earth', and 'osmos', meaning 'smell'. Geosmin is formed by cyanobacteria and the gram-positive bacteria 'Streptomyces'. Geosmin can be smelt when it rains on a dry soil. It decomposes under acidic conditions.

Answer: Strawberry

Furaneol has the chemical formula C6H8O3. It has two enantiomers, only one of which is responsible for the characteristic 'strawberry' smell. Furaneol is also present, to a small extent, in the smell of pineapples. Furaneol is also soluble in organic solvents. It consists of a pentagonal ring, whose one vertex is an oxygen atom.

Answer: Chloroxylenol

Chloroxylenol is a derivative of the compound xylenol, and contains a chlorine atom attached to the benzene ring opposite to the hydroxyl group. Its formula is C8H9ClO. It destroys the cell-wall of bacteria. Chloroxylenol is, however, toxic if ingested. It is also used in antibacterial soaps. Terpineol is another important constituent of antiseptics like Dettol.

Answer: Ethyl mercaptan

Ethyl mercaptan is also known as ethanethiol, with the formula C2H5SH. It is more volatile than ethanol. Although ethyl mercaptan is toxic in high concentrations, it is mixed in very low concentrations in Liquid Petroleum Gas (LPG) cylinders. This is because it diffuses in case of a leak, and our sense of smell is extremely sensitive to it.

Answer: Clove

Eugenol has the chemical formula C10H12O2. Eugenol contains a methoxy and a hydroxy group attached to a benzene ring. It is present in very high concentrations in clove bud oil and clove leaf oil. Eugenol, when present along with zinc oxide, is used to create a material used for dental fillings.

Answer: Esters

Esters are organic compounds produced when an organic acid reacts with an organic alcohol, which also produces water. Different esters have the characteristic smell of different fruits, and are hence used as flavouring agents in food. For example, isoamyl acetate has a characteristic 'banana' smell, while methyl butyrate has a characteristic 'pineapple' smell.

Answer: Peppermint

Menthol has the formula C10H20O. It is extracted from plants such as corn mint or peppermint, which itself is a cross between watermint and spearmint. Menthol also has local anaesthetic properties. Menthol melts at a temperature slightly above room temperature. Menthol triggers certain skin receptors when ingested, giving a cool sensation.

Answer: Camphor

Camphor is waxy and transparent. Its formula is C10H16O. It is primarily derived from the wood of the camphor laurel tree, with the scientific name 'Cinnamomum camphora', mostly found in southeast Asia. It is optically active, and it structure is similar to compounds like borneol. Camphor is also an ingredient in Indian cuisine.

Answer: Coffee

Furanylmethanethiol is a derivative of furfural, which can be prepared by the dehydration of glucose. Furanylmethanethiol has a bitter taste and gives the characteristic roasted smell of coffee. It is a clear colourless liquid, when freshly prepared. 3-mercapto-3-methylbutyl formate is another compound giving a roasted smell to coffee, while furaneol can give a sweet sensation.

Answer: Acetone

Acetone is the simplest ketone and has the chemical formula CH3COCH3. Acetone is used in the production of methyl methacrylate and bisphenol A. Acetone is also used as a cleaning agent. The most common method of preparation is the cumene process, where cumene is oxidised to phenol, giving acetone as a by-product.