Identifying Unknown Organic Compounds

Flashcards covering chemical reagents, observations, and reaction types used to identify alkanes, alkenes, alcohols, carboxylic acids, and amines.

Red Litmus Test (Amine)

The red litmus paper turns blue in the presence of an amine.

Blue Litmus Test (Carboxylic Acid)

The blue litmus paper turns red in the presence of a carboxylic acid.

Solubility of $C1-C4$ Organic Compounds

Organic compounds with 1 to 4 carbons mix into a single layer in water (soluble).

Solubility of $> C4$ Organic Compounds

Organic compounds with more than 4 carbons form two layers in water (insoluble).

Reaction of Alkanes with $Br_2(aq)$ (Bromine Water)

Observation: Orange to colourless slowly with UV light. Reaction type: Substitution. Product: Bromoalkane.

Reaction of Alkenes with $Br_2(aq)$ (Bromine Water)

Observation: Orange to colourless quickly. Reaction type: Addition. Product: Dibromoalkane.

Reaction of Alkenes with $H^+/MnO_4^-$ (Acidified Permanganate)

Observation: Purple to colourless. Reaction type: Oxidation. Product: Diol.

Reaction of Alcohols with $H^+/MnO_4^-$ (Acidified Permanganate)

Observation: Purple to colourless. Reaction type: Oxidation. Product: Carboxylic acid.

Reaction of Alcohols with $H^+/Cr_2O_7^{2-}$ (Acidified Dichromate)

Observation: Orange to green. Reaction type: Oxidation. Product: Carboxylic acid.

Carbonate or Hydrogen Carbonate Test

Used to identify carboxylic acids; results in characteristic bubbles of $CO_2$.

Metal Test

A physical test for identifying organic compounds that results in bubbles of $H_2$ gas.