ISSR CLASSES
Checkpoint Science
iGCSE Chemistry
iGCSE Physics
iGCSE Coordinated Science
A-Level Chemistry
PRACTICALS
Practicals Home
Practicals A-Z
Study Plan for Practical Work
Compound J
This is a colourless, neutral liquid. When a little solid phosphorus pentachloride is added steamy fumes are seen. When warmed with acidified sodium dichromate solution there is a colour change from orange to green. Oxidation of compound J with limited oxidizing agent yields a new organic compound K. Compound K turns warm Fehling's solution from blue to brick red.
Steamy fumes with phosphorus pentachloride suggests hydrogen chloride gas. A neutral organic liquid which reacts with phosphorus pentachloride is probably an alcohol. Only primary and secondary alcohols are readily oxidized by acidified sodium dichromate. The reaction with Fehling's solution indicates that compound K is an aldehyde. This shows that the original alcohol, J, must be a primary alcohol.
Answer: primary alcohol.