ask for vs request

ask for is not a noun while request is a noun.

Word	Noun	Adjective	Verb	Adverb
ask for	No	No	Yes	No
request	Yes	No	Yes	No

As verbs, ask for and request are synonyms defined as:

Other synonyms of ask for include bespeak, call for, quest.

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

ask for (verb)	request (verb)
express the need or desire for	express the need or desire for
increase the likelihood of	ask (a person) to do something
	inquire for (information)