The chapters in Chemistry are such that most of the chapters have nearly equal. It is rather proportional to the number of pages in NCERT devoted to a particular chapter.
NCERT textbooks continue to be the prescribed source of questions in board exams. Chapters of NCERT have to be done thoroughly to prepare well for your CBSE Class 12 Chemistry board exam.
Exemplar has been the source of surprising questions which can help your prepare well for your CBSE Class 12 Chemistry board exams.
CBSE has changed the chemistry board exam pattern. Hence, it is important to practice questions based on the new pattern to be well prepared.
Keep learning about your mistakes, rectify them and revise the chapters continue to do well in your CBSE Class 12 Chemistry Board Exam.
You should practice at least four full-length mock tests of Chemistry for your board exam. Go through the previous year's papers and spend more time on the known difficult previous year questions.