Question

how can u test qualitatively for the presence of alcohol, aldehydes, ketones, hallides &carboxylic acid?

Answer 1

\[\color{blue}{\text{Test for alcohol}}\]Reagents: PCl5 in dry conditions
Observation: Steamy fumes of HCl gas which turns damp blue litmus paper red
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\[\color{orange}{\text{Test for an aldehyde}}\]Reagents: Fehlings reagent or Tollen's reagent
Observation: Red precipitate when reagents are warmed with an aldehyde. Tollen's reagent gives silver mirror
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\[\color{green}{\text{Test for carbonyl (Aldehyde + Ketone)}}\]Reagents: 2,4-DNPH or 2,4-dinitrophenylhydrazine
Observation: Orange precipitate when added to a carbonyl
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\[\color{indigo}{\text{Test for a carboxylic acid}}\]Reagents: NaHCO3
Observation: CO2 gas which turns lime water milky