Where Class 12 students lose marks in Chemistry

The lowest-scoring chapter was Electrochemistry: students scored 40% of the marks on its questions, against 46% across the whole paper.

What examiners look for: Examiners mark this chapter point by point: the law or definition, the labelled diagram, the equation with units. Revise it from the marking schemes of past papers and practise writing each point in full, not just reading it.

Students scored 57% on 1-mark questions but only 36% on 3-mark questions, which made up 30% of all the marks lost.

What examiners look for: Two- and three-mark answers usually carry one mark per point. Write as many distinct points as the marks, each in its own line, instead of one long paragraph.

No answer was found for 3.3% of the questions, and these blanks made up 12% of the marks lost. (This includes answers we could not locate on the sheet, for example where the question number was missing.)

What examiners look for: CBSE board papers have no negative marking, so a blank answer is the only sure zero. Attempt every question, and write the question number clearly next to each answer so it is found and marked.

In attempted long answers (4 marks or more), 24% earned full marks and 55% earned part of them.

What examiners look for: Partial marks are the norm in long answers. The marking scheme lists the steps; the missed ones are usually the final unit, the conclusion, a labelled diagram or a justification.