Depends if you repeatedly asked me for chemistry help, said hello to me all the time, start conversations with me i think id get the hint. I guess if you just ask on the occassion id just take it as you wanting help. Nice thing about it is you really dont know whether its just asking for help or just to get to know someone better so you can play it to your advantage.
Id go for it i guess its a way to get into a conversation without the obvious I LIKE YOU effect. Maybe he will perk up and enjoy talking to you depends on how you play your cards.