Q. 6.103 - An Introduction to General, Organic, and Biological Chemistry

Question

Match each of the Lewis structures (a to c) with the correct diagram (1 to 3) of its shape, and name the shape; indicate if each molecule is polar or non-polar. Assume X and Y are non-metals and all bonds are polar covalent.

Step-by-Step Solution

Answer

a. Lewis structure a corresponds to shape $2$. It has trigonal pyramidal shape. It is polar molecule. 

b. Lewis structure b corresponds to shape $1$. It has bent shape. It is polar molecule. 

c. Lewis structure c corresponds to shape $3$. It has tetrahedral shape. It is non-polar molecule. 

Part(a) Step 1: Given information

We have been given the Lewis structure of  molecule a.

We need to find the correct diagram from 1 to 3 of its shape, name the shape; and also indicate whether the molecule is polar or non-polar. 

Part(a) Step 2: Explanation

The Lewis structure a corresponds to shape $2$.It has $3$ bonds attached to central atom and $1$ lone pair electron on central atom. Its shape is trigonal pyramidal with bond angles $<109.5°$. It is a polar molecule.

Part(b) Step 1: Given information

We have been given the Lewis structure of molecule b.

We need to find the correct diagram from 1 to 3 of its shape, name the shape; and also indicate whether the molecule is polar or non-polar. 

Part(b) Step 2: Explanation

The Lewis structure b corresponds to shape $1$. It has $2$ bonds attached to central atom and $2$ lone pairs of electron on central atom. Its shape is bent because of presence of $2$ lone pairs of electron . It is a polar molecule.

Part(c) Step 1: Given information

We have been given the Lewis structure of molecule c.

We need to find the correct diagram from 1 to 3 of its shape, name the shape; and also indicate whether the molecule is polar or non-polar. 

Part(c) Step 2: Explanation

The Lewis structure c corresponds to shape $3$. It has $4$ bonds attached to central atom and no lone pair of electron on central atom. Its shape is tetrahedral with bond angle $109.5°$. It is a non-polar molecule.