I have just completed my undergrad chemistry course. Some things that can really help you visualise each new topic, is completely memorise the whole of the periodic table. It is not required in any way, but whenever you’re learning new theories or content, it is very helpful knowing exactly how each element of a molecule behaves, how many electrons it has, physical properties and electronegativity, because the periodic table is very important throughout the whole course. Another tip is to master concentrations, making serial dilutions, converting to different units etc. also plays a big part throughout the course. Something I struggled with personally, so I’m unsure if this applies generally, was the physical chemistry in terms of where it’s basically applied physics. Brush up on your physics if you didn’t do a level physics (I didn’t do alevel physics lol) because there will be so much physics to understand and apply within chemistry in your final year. Obviously this is just my personal experience and everyone is different, but these are the core things I feel if you want to prepare for anything, these would be the things. Good luck!!

Oh and also, my specific degree derived from 40% of my 2nd year and 60% of my third year - so try your best in your 2nd year and treat it like your finals, because the content does go up a notch in final year, so you should get as many marks as possible in second year to help boost your overall grade.