Alcohols, Ethers and Carboxylic Acids

The carbonyl group (C=O) is present in all three compound types: ketones (RCOR'), aldehydes (RCHO), and esters (RCOOR'). Each contains a carbon-oxygen double bond as a defining functional group.

Potassium (K) forms a +1 ion, and hydroxide (OH) is a -1 polyatomic ion. They combine in a 1:1 ratio to give KOH. K2OH would imply K2+ which doesn't exist, and K(OH)2 would require a +2 charge.

Methanol (CH3OH) is historically called 'wood alcohol' because it was originally produced by destructive distillation of wood. It is not fruit alcohol, anesthesia, or 'none of the above'. It is toxic and used as an industrial solvent and fuel.

C6H5OH is the molecular formula for phenol, which consists of a benzene ring (C6H5) bonded to a hydroxyl group (OH). Methanol is CH3OH, ethanol is C2H5OH, and propanol is C3H7OH.

Dried cow dung emits methane (CH4), the simplest alkane. This is because cow dung contains organic matter that undergoes anaerobic decomposition, producing methane gas. C2H4 is ethylene, CH3 is a methyl radical (not a stable molecule), and 2CH3 is not a valid chemical formula. Methane is a major greenhouse gas.

The -F functional group is called fluoro (option D intended, though spelled 'FLORO' with a typo). The correct systematic name is 'fluoro'. Asid (A) appears to be a typo for acid (-COOH), alcohol (B) is -OH, and ester (C) is R-COO-R'. Fluoro compounds include Teflon and many pharmaceuticals.

The -OH functional group is called alcohol (or hydroxy when named as a substituent). Alcohols contain the hydroxyl group bonded to a carbon atom. Alkene (A) refers to C=C double bonds, chloro (B) is -Cl (with typo), and amide (D) is -CONH2. Common examples include ethanol and methanol.

Hairsprays and similar aerosol products historically used CFCs as propellants, and foam cups (styrofoam) are made using expanded polystyrene, which involves CFCs or related chemicals in production. VOCs are also emitted from many such products and materials. All three (VOCs, CFCs, and related chemicals like CO2 from production processes) are valid environmental concerns associated with these products.

Acetylene gas is produced by reacting calcium carbide (CaC2) with water (H2O), producing acetylene and calcium hydroxide. The chemical reaction is: CaC2 + 2H2O → C2H2 + Ca(OH)2. This is the standard industrial method for generating acetylene gas for welding.

Acetic acid in diluted form (typically 5-8%) is vinegar. Vinegar is primarily water and acetic acid, giving it its characteristic sour taste and preservative properties.

Aldol condensation requires compounds with alpha-hydrogens. Aldehydes (option A) and ketones (option B) have alpha-hydrogens and can undergo aldol condensation. An aldehyde and ketone combination (option C) can also undergo aldol condensation. However, esters (option D) generally do not have acidic alpha-hydrogens in the same way and cannot participate in classic aldol condensation reactions under normal conditions.

This option is correct because when liquid acetic acid is mixed with ethanol and a drop of concentrated sulphuric acid, it forms ethyl acetate which emits a fruity odour.

This option is correct because when para-nitroso N,N dimethyl amine is decomposed with caustic soda, it forms dimethyl amine and para-nitrosophenol.