Explain the addition of ammonia and its derivatives to aldehyde and ketone compounds.

(N/A) The reaction of aldehydes and ketones with ammonia derivatives $(H_{2}N-Z)$ is a nucleophilic addition-elimination reaction.
$(1)$ Mechanism:
Nucleophiles,such as ammonia and its derivatives $(H_{2}N-Z)$,add to the carbonyl group of aldehydes and ketones. The reaction is reversible and acid-catalyzed. The equilibrium favors the product formation due to the rapid dehydration of the intermediate to form $C=N-Z$.
General reaction:
$>C=O + H_{2}N-Z \rightleftharpoons >C(OH)NHZ \xrightarrow{-H_{2}O} >C=N-Z$
$(2)$ Addition of alcohols:
Aldehydes react with one molecule of monohydric alcohol in the presence of dry $HCl$ gas to form hemiacetals,which further react with another molecule of alcohol to form acetals.
$(3)$ Cyclic ketals:
Ketones react with dihydric alcohols like ethylene glycol in the presence of dry $HCl$ gas to form cyclic products known as ethylene glycol ketals.
$(4)$ Hydrolysis:
Acetals and ketals are hydrolyzed with aqueous mineral acids to yield the corresponding aldehydes and ketones.