$1-1)$ Is a process during which no entropy is generated $)=(0$ necessarily reversible?

$1-2)$ Consider an environment of zero absolute pressure $($such as outer space$).$ How will the

actual work and the useful work compare in that environment?

$1-3)$ It is well known that the actual work between the two states depends on the path

followed during the process $($i$.$e$.$ path dependent$).$ Can we say the same for the

reversible work?