Before it was revealed that Hal was the Black Hood... Betty discovers that Chic Cooper isn't her brother at all. In fact, he murdered her real brother (his old roommate).
Because of this, Betty unleashes the Black Hood on him. The last we see of Chic is him running with a small head start away from the Black Hood.
The finale didn't clarify whether he made it out alive or not... but we think that Madchen Amick (Alice Cooper) just gave it away.
At an event for mental health awareness, Madchen talked about season three and her role playing alongside Hart Denton (Chic Cooper). She said, "I’m sure you’re all aware of [Hart’s] creepy portrayal of the Cooper son and I can’t wait to see what he’s gonna be up to in season three. Spoiler alert!"
As creepy as he was, we're so glad he'll be continuing the show. As for who the real Cooper brother is, you can read the most amazing fan theory about that right here.