Exhaust and "Frozen Mallet" are fine ONLY if you are trying to stop people from running. Take a look at my "Jax the Trapper" build. http://www.mobafire.com/league-of-legends/build/jax-the-trapper-33839

By the way, sword of the divine is REALLY good teemed with Jax's ulti passive. Just a suggestion. =D

Exhaust is good though, but "Frozen Mallet" is not!
"Offensive mastery" is not that good ether as soon as you are level 6 you do not have any problems with minions, Jax is one of the fastest minion killers in league.

Maybe take a look on my build, but it is more hybrid than yours, in sum over all the game I do about half magic and half physical damage:
http://www.mobafire.com/league-of-legends/build/patched-jax-19129

Your build Isn't bad, I would just change a few things; First off exhaust.. Jax needs his dodge to proc in order to use his counter strike, if they cant even attempt to hit you, your dodge cant proc. Second, you need to pick up the spell pen in your mastery tree, b/c all of Jax's abilities deal magic damage, so this would help quite a bit. Third, health on Jax.. why buy health, when you can buy damage and it give you health..? Fourth: I personally would max out counter strike by level 9.. Look at my Jax build and try it, its somewhat close to yours but with slightly less attack speed and a lot more attack.
But I'll vote it up.