can a chipmunk .22 rifle kill a fox?

yes, with a well placed shot of course, but a centerfire .22 would do a better job.

Can it? Sure can if you get a good shot to the brain bucket at the head of the spine. The biggest question is SHOULD it be used? No. You should use a .22Mag at the very least (still taking a head shot). If you are just shooting at the vitals, then I would suggest something with a little more power like a .223 varmint round.

There are documented cases of grizzlies being killed by .22 long rifles. I wouldn't want my life to depend on a .22 killing a grizzly, but I think it does prove emphatically that the round will kill a fox.

A 22 could kill anything from a small rat to a coyote.

you can kill a black bear with a .22

Without a doubt!

Yup

Kills groundhogs pretty nice too.

a good clean head shot will

Yep.

any gun powder load can take down small game.