Question

Draw a lewis structure for hccl3. Show all unshared pairs and the formal charges

Answer 1

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

The given molecule is, $HCCl_3$

Carbon has '4' valence electrons, hydrogen has '1' valence electron and chlorine has '7' valence electrons.

Therefore, the total number of valence electrons in $HCCl_3$ = 1(1) + 1(4) + 3(7) = 26

According to electron-dot structure, there are 8 number of bonding electrons and 18 number of non-bonding electrons.

The electron-dot structure of $HCCl_3$ is shown below.

Now we have to calculate the formal charges on carbon, hydrogen and chlorine.

Formula for formal charge :

$\text{Formal charge}=\text{Valence electrons}-\text{Non-bonding electrons}-\frac{\text{Bonding electrons}}{2}$

$\text{Formal charge on carbon}=4-0-\frac{8}{2}=0$

$\text{Formal charge on hydrogen}=1-0-\frac{2}{2}=0$

$\text{Formal charge on chlorine}=7-0-\frac{2}{2}=0$