CBSE Board Exam 2019: ‘Maths, Reasoning are heart of Chemistry’

Reasoning and mathematics are at the heart of chemistry, says Sanju Malhotra, a subject expert who has been coaching students for the last seven years. Math will come in handy for a good score in chemistry, he advises students.

Those with a good grasp of math can start with chapter 1 to chapter 4, which have numerical. Topics including solid state, solutions, electrochemistry, and chemical kinetics can help one build up a good score as questions worth 12 or 14 marks are set from these chapters, Malhotra adds.

However, for students with better reasoning and analytical ability, who are good with the theoretical part of chemistry, Bindu Malhotra, a teacher at Government Model Senior Secondary School, Sector 38, says, “If you feel your learning and cramming capabilities are stronger, you should focus on chapter 6 to chapter 9. These chapters include organic chemistry.”

Chapters such as p-block, d and f block and coordination chemistry can be easy to crack. In fact, p-block has eight marks. Coordination chemistry includes nomenclature which is not hard either, she says. “There are many reasoning based questions framed out of this segment, primarily from p block and d and f block. It is easy to answer once you have read the chapter.”

Students who are lagging in studies and want to pass the exam at any cost should not leave out the last three chapters. These are the easiest and can help them get a high score without having to bank on any complex numerical or reasoning questions. “These include biomolecules, polymers and chemistry in everyday life and can help one score at least 10 marks,” adds Malhotra.

“While doing organic chemistry, which forms a major portion of the syllabus, students should focus on name reactions. Reactions like aldol condensation, Hell–Volhard–Zelinsky halogenation reaction , Cannizzaro reaction, carbylamines reaction, Sandmeyer reaction, Rosenmund reduction, Kolbe–Schmitt reaction or Kolbe process, Reimer–Tiemann reaction , Hoffman bromamide reaction are very crucial. Every year questions of three marks are framed from these reactions.

Another question from organic chemistry is ‘distinguish between the two,’ for example, differentiate between aldehyde and ketones, phenol and benzoic acid, primary, secondary and tertiary amines etc,” says Bindu.

Teacher’s profile

Understand and memorise all the formulas

Neenu Rajwanshi, a teacher at Government Model Senior Secondary School, Sector 33, hands out a few tips to ace the chemistry paper, saying there are a few reactions and conversions which are repeated almost every year in the exam. Check out sample papers of the last five years and figure out the pattern of questions.

To pass the exam you need 23 marks out of 70, which is not difficult at all. Just focus on the NCERT textbooks. Look at the examples as well as the exercises and go through both the solved and unsolved questions, she says.

The entire chemistry exam is NCERT based and there are two books for Class 12. Questions of 42 marks are based on book-I. Book-II is worth 28 marks; go through both thoroughly, Rajwanshi adds.

“For last-minute revision, I advise my students to do a couple of things. Write formulas of all the chapters which include numerical. It helps a lot during final preparations as students can then apply the right formula and directly solve the questions during the exam.”

In reasoning-based questions reading sample papers of the last five years is important. Students will get an idea of how these questions are framed, she says.

There are no diagrams in chemistry. However, students must go through a graphical question on Lanthanoid contraction. Expect a three-mark question from this part, she says.

The sequence of attempting the paper does not matter as long as the question number is mentioned – which students sometimes forget. Also, all parts of the question should be done together. Marking in the paper is done stepwise, so students will be awarded marks for whatever they have written. Value points should be underlined. If short of time students should write the formula in the numerical and do the calculations after completing the rest of the paper. Log tables are available during the examination for calculations, concludes Rajwanshi.

TOPPER TALK

Revise the entire syllabus for your pre-boards

Harleen Kaur Bedi, who scored 92.8% in Class 12 (medical), Sacred Heart School, Sector 26, and is now a student at the Government Medical College and Hospital, Sector 32, talks about how she aced the boards.

How did you study? Your favourite and least favourite subjects?

Frankly speaking, I had no fixed formula for studying. For me, quality matters more than quantity so I usually focused on spending the peak hours of the morning more judiciously. My favorite subject was biology, but I was not very interested in chemistry.

Your strategy for tackling each subject?

It’s important to focus on NCERT and for physics one should devote more time on numerical and derivations. For chemistry, it is important to practice NCERT numerical and examples.

How many hours of study did you put in a day?

I gave five to six hours to each subject apart, from tuition and coaching classes.

How did you cover the entire syllabus?

Studying for tests every month and pre-board exams helped me cover the entire syllabus.

Relaxation tips?

I used to listen to music and took short power naps.

Your daily schedule during the exams?

Nothing special. I concentrated hard while studying and did not bother much about my results of percentage.

Any tips for students and their parents?

Students should not be disheartened by low grades during pre-boards and class tests because these indicate a students’ level of preparedness. Parents too should take this positively and encourage their children to concentrate and focus on improving their mistakes and turning their weaknesses into strengths.

Any tips to bust stress during exams?

One can relieve stress by exercising and getting advice from seniors and adults on tackling commonly faced problems during exams

How do you manage to study for the boards along with medical or engineering college entrance examinations?

For cracking any entrance exam it is important to not only focus on the Class 12 syllabus but also on the Class 11 syllabus. Revise the Class 12 syllabus during pre-boards thoroughly so that you don’t have to work extra hard while preparing for the competitive exams. Make it a point to write all the Class 11 tests in January and February.

As told to Rachna Verma