There are many capable laptops that have GPUs inside them. Though if you want to play games at 4k the price then is bonkers.
I would say the most I would spend is for a laptop with a GTX 1060 inside, 1050TI at minimum.
Though you are in college. And some classes can last for hours, so battery life is VERY important. You can't have low price, high performance and good battery life at the same time.
Several machines pop up as good ideas:
Though most inconspicuous laptops that have dGPUs are not cheap.
If you have an unlimited budget I would recommend something like the GS63VR Max Q or Razer blade, but lets be honest you aren't going to spend 2k+ on a laptop.
Though Thunderbolt 3 allows for an interesting system. Sadly your gonna end up spending just as much as the Blade or GS63.
Now desktops have an interesting comeback to the portability issue.
Mini ITX. Think of it like a normal motherboard just leave 1 PCI-Express x16 slot, 2 ram slots and a CPU socket. You can get some VERY small machines with this. Though you pay a price. Smaller boards cause more expensive methods of cramming all the hardware on (i.e. Asus slapping Daughterboards on motherboards for Power Delivery). Also smaller cases apparently cost more.
You could even bring it to the library (may look just unusual) and get a cheaper but not horrid laptop for portable use (Remote access is the key).
Now you say your doing chemical engineering. If you have to do things like use computers to do things like calculations and very heavy loads, then just make sure to bring the power brick.