Put yourself in the shoes of other people on your course who, if forced to go faster might think the class is going far too fast and can't cope. You both can't win.
You could consider reading ahead in your book? Or reading around the subject and learning some chemistry not on the OCR A spec.? Have a look at the OCR B or the Cambridge Pre. U. specs. to give you a few ideas. Alternatively, there are plenty of books people will recommend: most suggest "Why Chemical Reactions Happen", I really like "Chemistry3".