That would depend on whether or not your law school application asks about past criminal convictions, including DWIs. Also, it would depend on whether they did a background check. That is probably a question to direct to the applicable law school.
The other thing to keep in mind is that you have not been convicted yet. And hopefully you will not be. DWIs are almost always able to be defended. Talk to a properly qualified Arkansas DWI lawyer if you want to know how your case might be defended and WON. An arrest is NOT a conviction.
Not only may the law school inquire about your criminal history on your application, but your bar application will almost certainly ask about criminal convictions including alcohol offenses.
I will echo Mr. Williams' answer. Immediately consult with a DWI defense attorney. We defend cases like this every day and there are many ways to attack the prosecution's case.
There are many qualified attorneys on this website. Don't delay.