Solution:
(iii) Semicabarbazone:
Semicarbazone is made up of aldehydes and ketones, and it is generated when a ketone or aldehyde reacts with semicarbazide. The reaction type is condensation.
Aldehydes and ketones are identified and characterised using semicarbarzones.
(iv) Aldol:
A beta-hydroxy aldehyde or ketone is an aldol. It is made when two molecules of the same or a single molecule of two different aldehydes or ketones react together in the presence of a base.