Most of my chemistry class did maths a-level, and the one person who didn't, got an A, whilst the others struggled with chemistry and maths. As long as you can rearrange and do basic maths calculations you'll be find with the majority of the content. There is some logaritms in it, but I'm sure your teacher will explain, and even if you don't understand it, just remembering the method of how to use them will be good enough.