AOA..one thing i would like to suggest that if you have not done masters in chemistry than please do not go for this subject in CSS..........it can ruin your whole result chemistry papers are always conceptual, often very tough and very lengthy syllabus..... you can not take risk to leave even a single topic as each question contains three to four parts and all mostly covering different topics.So i will suggest please once go through last 6 to 7 years papers you will by yourself realize that you should go for this or not?specially chemistry paper II 2009 best of luck every one... ALLAH pak bless you with the best always ameen sum ameen