CBSE-X Board 2010: Chemistry Preparation

Posted by TCYonline.com on December 8, 2009

As we know that CBSE – X exams are approaching, bringing with them the feeling of fear and nervousness. Although the grading system in class X Board – 2010 exams has helped the students a lot to fight this fear, yet the building of pressure in any exam is natural. Some students perform better under stress, while others totter as their poor nerves are stretched to the limit.

Adding to this, are subjects like Chemistry in CBSE exams – 2010, requiring the students to cram the chemical reactions and equations. Fumbling with nomenclature in carbon and its compounds, mugging up the extractions in metals and non–metals is observed in the students to an extreme extent.

To combat these issues and perform well in final board exam and also pre board exams, you should first of all be aware of the marking scheme followed by CBSE in board examination of 2010. This involves 3 very short questions carrying 1 mark each, 2 questions carrying 2 marks each, 2 short questions carrying 3 marks each and 1 question carrying 5 marks. There is no choice except the internal choice in the 5 mark question.

To equip you more on this, let us discuss deeper into a few problem areas in pre board and CBSE – 2010 Final Board examination, as given below

• Formulae of chemical compounds
• Electron dot structure of chemical compounds

1. Structure of carbon compounds

–This kind of question is generally of 5 marks in your board exam. If you are given the name of an organic compound, let’s say, Hexanol, and then simply split the name of the compound to draw its structure

Hex – an – ol

Hex – C-6

an – Single bond

ol – OH

and then simply draw the structure–

Let us take one more example to make it clearer –Butanoic acid

Again split the name of the compound into parts

But – an – oic acid

But –  C–4

an – Single Bond

oic acid –

O
||
C – OH
and then draw the structure as,

Now you can practice with as many numbers of examples you want

Another important thing for CBSE – 2010 exams that how to remember the formulae of chemical compounds:

Topic No. 2: Formulae of chemical compounds

– Never ever learn the formulae of compounds

– This topic is the base of Chemistry and comes across as a cumbersome problem. Maximum Chemistry questions in boards and pre–boards call for the clarity of this concept.

To make it easier for yourself, make a table of the valencies of various positive and negative ions.

This way you would be able to learn the valencies of various ions and then you would never need to learn the formula for any compound. Make the formula by the same general method of criss–cross valency as you did in Class IX.

® Electron dot structure of chemical compounds

For this sure shot question in your CBSE Board exams, you simply need to learn the atomic number of first 20 elements for which you can develop a mnemonics also.

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So you can simply learn these by developing your own methodology. Write the electronic configuration for the element, and using its only valence shell electrons, draw the structure for it. Never write the inner shell electrons while drawing the structure.

e.g. Fluorine – Atomic number – 9

Electronic Configuration – 2, 7

We wish all of you to do well in your CBSE – 2010 Board exam and Pre–Board exams.