describe: (a) the complete and incomplete combustion of alkanes (b) the free-radical substitution of alkanes by \( Cl_2 \) or \( Br_2 \) in the presence of ultraviolet light, as exemplified by the reactions of ethane

state the names and formulas of the common acids, limited to hydrochloric acid, HCl, sulfuric acid, \( H_2SO_4 \), nitric acid, \( HNO_3 \), ethanoic acid, \( CH_3COOH \)