I often get students telling me that they know the content but don’t do well on exam questions. If you are doing well on topic tests but not on your mock exams, it is likely that either the topic tests are missing some of the key details the examiners are looking for, or that you haven’t faced sufficiently challenging questions often enough.
What makes a question difficult? Synoptic questions (those that combine or test ideas from different topics), those covering practical chemistry and unusual calculations feature frequently as the most difficult on the exam.
What can you do to prepare for the interview? Every October, students who are applying to Oxford or Cambridge put the finishing touches to their personal statements, mail off their applications and then inevitably start wondering if they will be good enough by December to win a place. I used to stay up at Oxford during the interview period whilst an undergraduate and I was also there at a similar time at Cambridge as a graduate.
