tt o N be C re ER pu T bl is he d
The Department of Education in Science and Mathematics DESM , National Council of Educational Research and Training NCERT , initiated the programme for the development of Exemplar Problems in science and mathematics for secondary and higher secondary stages based on the subject textbooks developed on the bases of the NCF-2005. The present book is based on the contents of the Chemistry Textbook for Class XI published by the Council in 2006. The main objective of the book on Exemplar Problems in Chemistry is to provide the teachers and students a large number of quality problems in various forms and format with varying levels of difficulty to facilitate teaching-learning of concepts in Chemistry that are presented through the Textbook for Class XI. It is envisaged that the problems included in this book would help the teachers to design tasks to assess effectiveness of their preparation of balanced question papers for unit and terminal tests. The feedback based on the analysis of students responses may help the teachers in further improving the quality of classroom instructions. In addition, the problems given in this book are also expected to help the teachers to perceive the basic characteristics of good quality questions and motivate them to frame similar problems on their own. Students can benefit themselves by attempting the problems given in the book for self assessment and also in mastering the basic techniques of problem solving. Some of the problems given in the book are expected to challenge the students understanding of Chemistry concepts and to apply them in new situations. At number of places elaboration of answers may be required. The problems included in this book were developed in workshop mode organised by the DESM involving practicing teachers, subject experts from universities and institutes of higher learning, and the members of the Chemistry group of the DESM whose names appear separately. I gratefully acknowledge their efforts and thank them for their valuable contribution in our endeavour to provide good quality instructional material for the school system. I especially thank Professor Brahm Parkash, Dr. Alka Mehrotra, Dr. Anjni Koul and Ms. Ruchi Verma of DESM for editing and refining the problems and for making the manuscript pressworthy. Thanks are also due to Professor Brahm Parkash of DESM for coordinating this programme.
I also thank Shri Ishwar Singh, Sr. DTP Operator for typing the manuscript and preparing a press-ready copy. We look forward to feedback from students, teachers and parents for further improvement of the contents of the book.