request vs pass on

request is a noun but pass on is not a noun.

Word	Noun	Adjective	Verb	Adverb
request	Yes	No	Yes	No
pass on	No	No	Yes	No

As verbs, pass on is a hypernym of request; that is, pass on is a word with a broader meaning than request:

Other hypernyms of request include communicate, pass, pass along, put across.

request (noun)	pass on (noun)
the verbal act of requesting
a formal message requesting something that is submitted to an authority

request (verb)	pass on (verb)
express the need or desire for	transmit information
ask (a person) to do something	cause to be distributed
inquire for (information)	move forward, also in the metaphorical sense
	give to or transfer possession of
	place into the hands or custody of
	transmit (knowledge or skills)
	refer to another person for decision or judgment