TIPS TO CRACK SHAPE OF THE MOLECULE:

TIPS TO CRACK SHAPE OF THE MOLECULE:

Are you feeling dejected in solving shapes of the chemical molecules?
Then this article might help you

But now the problem is how to find lone pair and bond pair...

That is the next technique

TRICK TO FIND L.P, B.P AND HYBRIDISATION

Let's consider NH3  as an example now.

1. First find the central atom which had undergone hybridisation and find its outershell electrons and write as below:

                N •

              •

              •

              •

              •

(Nitrogen has 5 elecrons in its outermost shell and so five dots)

Now three hybrogens are bonded to it.So write as below

           N •─H

              •─H

              •─H

              •

              •

Therefore from above it is clear that,

1. There are three B.P(sigma bonds) and two L.P.
2. If there is any charge on the molecule,

•               For +ve charge reduce the number of electrons equal to the charge and
•               for -ve charge add the same

Now add the both to get T.P(Total pair=Sigma+lone pair)
   Therefore now from the table below,you can find hybridisation easily

Now you can find geometry easily from below table

NOTE:

There is a pretty good exception to the above rule i.e if there is oxygen in the side chain ,you must consider the double bond formed by oxygen to be a single one only to arrive at the answer

Eg: Consider SO2

Hope you understood and all the best

Share with your friends and comment if you have any doubt

See the updated tricks in inorganic chemistry for you