Hi,
I'm in my fourth year of chem eng at the moment so I'll try and give you some info about it.
The difference is basically this: chemistry is science and chemical engineering is engineering. It sounds obvious, but really it means a lot in practice.
Chemistry is very scientific. You will probably spend a lot of time in the lab. You usually have a lot of contact hours, and the work tends to be very mathematical/computational.
In chemical engineering, there is usually a small chemistry component but its very "shallow" i.e. it doesn't delve too deeply. Theres a lot more emphasis on classical mechanics (not quantum) e.g. heat, reactions, diffusion. Engineering is heavily project based too, so expect a lot of group work, not a pile of labs, some business-y/finance bits, and probably heavy use of computers. Chem eng is based on "processes" i.e. the equipment/equations/maths used to create a product, so there's a lot more focus on the large scale.