How To Keep CBSE Class 12 Chemistry Mistakes At Bay

Written By: Sashikanth Sai

The CBSE Class 12 board examination is in full swing and students are all set to take the Chemistry paper on March 13, 2018. Most of the students know the importance of Chemistry marks and put their best foot forward to grab a perfect score. Due to some silly errors, students fail to achieve the perfect score.

We know that the Chemistry subject consists of three sections, namely Physical, Organic and Inorganic Chemistry. And most of the students commit mistakes in all the three sections without realising them. The errors committed by the students have nothing to do with the subject knowledge; however, they can be easily avoided with a few precautions.

Here, we try our best to help students by listing out where the students exactly miss the bus. Take a tour of the points meticulously.

Physical Chemistry

  • In a numerical question, half or one mark is assigned for writing the formula, posting data related to working formula, perfect numerical value and proper unit. Students usually commit mistakes in these areas. They need to check the compatibility of all the units.
  • Students have to write all the laws as it is stated. They usually write the mathematical expression or reframe the statement., however, students need to be aware of the fact that marks are only allotted to the statement of law.
  • Students have to be more careful while plotting a graph. They need to write both independent and dependent variables.
  • Students need to write both cause and consequence for the reason based questions.

Inorganic Chemistry

  • If questions are asked related to geometry or draw a molecule, students need to just draw and do not write anything.
  • Students have to show the lone pairs of electrons whenever required.
  • The balancing of the equation is a must task for students. They need to be cautious about when a question is asked about the observation of a reaction, because students mistakenly write the equation.
  • As addressed in the Physical Chemistry, students need to answer the consequences for the reason based questions on the Inorganic Chemistry also.
  • Never forget to mention the principles while writing the process or steps.

Organic Chemistry

  • Usually, students commit error while writing the suffix and/or identifying the substituted alkyl group. Be attentive.
  • Students have to be more careful in the distinction between the pair of organic compounds. They usually make a mistake in not writing the reagent or writing the name of the test. This has to be rectified. resolved as early as possible.
  • Be attentive while writing the structure/formula, because the answer must correspond to the question.
  • Evaluator of the exam expects all the reagents involved steps in the conversion. So display all the steps.
  • Students are expected to show the arrows transferring the electron and types of reactions involved in the mechanism. So never miss this.
  • As we stated above in Physical and Inorganic Chemistry, cause and consequence are required for answering reason based question.


The final advice before you step into the examination hall from our end is try to maintain the word limit for the Chemistry paper and highlight all the key words. The chemistry paper requires effective time management. We wish you good luck!


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