The right to work implies the obligation on the part of the government to give a job to all the unemployed.
Can I replace all the unemployed with every unemployed. If yes then OK, but if not then why not?
No, you can not replace "all the unemployed" with "every unemployed" because "the unemployed" is an adjectival noun and thus itself actually means "unemployed people," i.e. in the plural.
When understood that way, it becomes quite illogical to say "every unemployed" as that would refer to "every unemployed people." :)