In the extraction of iron, limestone is added as a flux to remove: MCQ with Answer and Explanation

Explanation:
Ethanol (CH₃CH₂OH) and dimethyl ether (CH₃OCH₃) have the same molecular formula C₂H₆O but different functional groups: alcohol (-OH) vs ether (-O-). This is functional group isomerism. Ethanal is C₂H₄O, acetic acid C₂H₄O₂. Methoxymethane is another name for dimethyl ether. Functional isomers exhibit different chemical properties; ethanol reacts with Na, ether does not.

Explanation:
CH₃CH₂OH is ethyl alcohol or ethanol. Methanol is CH₃OH. Propanol C₃H₇OH. Butanol C₄H₉OH. Ethanol is the active ingredient in alcoholic beverages and used as biofuel.

Explanation:
Heating coal in the absence of air (destructive distillation) produces coke (solid residue, high carbon), coal tar (mixture of aromatic compounds), ammoniacal liquor, and coal gas (H₂, CH₄, CO). Coke is used in blast furnace. Coal tar is a source of aromatic chemicals and pitch. Coal gas was used for lighting historically.