-Transport Processes: involves understanding the mechanics behind the transfers and learning to derive equations under certain conditions and applying them to similar scenarios or using them to find a certain variable. For example would be to derive the equation for a fluid going through a circular pipe, calculating the pressure it exerts and then calculate the same pressure for a pipe with 4x the diameter.
-Principles of chemical processes: where you are taught how operations such as distillation, extraction and adsorption work, as well as learning the methods in deducing what actually happens with said operations through equations and also finding unknown variables (e.g. find the flow rate of the product). You'll even learn to do this in programming!
-Financial aspects and management: basically a turned-down version of economics, where you learn the best ways to increase income, decrease costs and maximize profit. You'll also learnt the basics of managing projects and tasks.
-Maths: Basically A-level maths and further maths, a bit of statistics and decision maths. You'll find that the stuff you learn in maths is applied to what you learn in chemical engineering. So make sure it's up to scratch!
-Thermodynamics: A stretch of A-level physics and finally understanding the simplest way of how fridges and engines work
It's a bit much and I tried not to go into too much detail, otherwise I'd be here forever!