Go in with no expectations. I am also chemical engineering grad, but my internship was at AMD. Not really related to my degree at the time but your aim should be to see how the industry functions, or rather how working life is. When u finally work, you sometimes end up in a different field. You have to learn again, but your takeaway from these internships is how to adapt and how to learn fast. Its not so much about the technical details. Everywhere you work, you most likely need to re-learn.

Dont worry so much about if the internship is hard, i think better if its hard. The new grads really need to toughen up, my opinion. Sometimes if I give fresh grads something out of their comfort zone, they start to tarik muka, overstress and begin to complain that this isnt what they spent 4-5 years in uni for. I think sometimes its good to go out of your comfort zone and see how you can contribute and grow also.