deduce the molecular and/or empirical formula of a compound, given its structural, displayed or skeletal formula

deduce the presence of a CH\(_3\)CO– group in an aldehyde or ketone, CH\(_3\)CO–R, from its reaction with alkaline I\(_2\)(aq) to form a yellow precipitate of tri-lodomethene and an ion, \( RCO_2^-\)

deduce the presence of a CH\(_3\)CH(OH)- group in an alcohol, CH\(_3\)CH(OH)-R, from its reaction with alkaline I\(_2\)(aq) to form a yellow precipitate of tri-lodomethane and an ion, \( RCO_2^-\)