General Chemistry

First, we need to draw the Lewis structure of H2O.

In short, these are the steps you need to follow for drawing a Lewis structure:

1.  Write the correct skeletal structure for the molecule.

        *   Hydrogen atoms are always terminal (only one bond)

        *   Put more electronegative elements in terminal positions

2. Sum the valence electrons from all the atoms.

3. Use a pair of electrons to form a bond between each pair of bound atoms.

4. Add the remaining electrons to satisfy the octet for a more electronegative atom first.

5. If any atoms lack an octet, make a double or triple bond to give them an octet.

There are 7 + 3×6 + 1 = 26 electrons. The chlorine goes in the middle with one lone pair, and the oxygens take 6 electrons each as three lone pairs:



As drawn, the oxygens are going to be negatively charged, which would mean a -3 ionic charge. Therefore, two oxygen will use one of their lone pairs to make a double with the chlorine. The other oxygen is then negatively charged:



The central atom has 3 atoms and one lone pair, therefore, the electron geometry is tetrahedral and the molecular geometry is trigonal pyramidal.


Steric number four corresponds to sp3 hybridization.


Check this 99-question multiple-choice quiz on Geometry and Hybridization:


Geometry and Hybridization Quiz

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