Cl-C-Cl vs H-C-H Bond Angles in CH4 & Dichloromethane

In summary, the bond angles in CH4 (methane) and dichloromethane (CH2Cl2) differ due to the presence of chlorine atoms in dichloromethane. This is because the chlorine atoms have a larger atomic radius, causing a slight increase in the bond angle. The bond angles also affect the overall shape of the molecules, with methane having a tetrahedral shape and dichloromethane having a distorted tetrahedral shape. Other factors that can influence bond angles include the presence of lone pairs of electrons and double or triple bonds. These bond angles can be determined experimentally through methods such as X-ray crystallography, NMR spectroscopy, and IR spectroscopy.
  • #1
jnimagine
178
0
How is the bond angle for Cl-C-Cl in dichloromethane different from H-C-H bond angle of CH4? Is it smaller??
 
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  • #2
What is the size of Cl vs. H in your examples?
 
  • #3
Chlorine has three free electron pairs, hydrogen has none. Because of the electon pairs chlorine atoms repell from each other more strongly so the Cl-C-Cl bond angle should be bigger than H-C-H. I am not sure of this, but it seemed logical to me.
 

FAQ: Cl-C-Cl vs H-C-H Bond Angles in CH4 & Dichloromethane

What is the difference between Cl-C-Cl and H-C-H bond angles in CH4 and dichloromethane?

The bond angles in CH4 (methane) and dichloromethane (CH2Cl2) are different due to the presence of chlorine atoms in dichloromethane. In CH4, all the bond angles are 109.5 degrees, while in dichloromethane, the bond angle between the carbon and the two chlorine atoms is around 111 degrees, and the bond angle between the carbon and two hydrogen atoms is around 107 degrees.

Why do the bond angles in dichloromethane differ from those in methane?

This is because the chlorine atoms in dichloromethane have a larger atomic radius compared to hydrogen atoms in methane. This larger size creates a bigger repulsion between the bonded atoms, resulting in a slight increase in the bond angle.

How do the bond angles affect the overall shape of the molecules?

The bond angles determine the shape of molecules in three-dimensional space. In methane, the bond angles are all 109.5 degrees, resulting in a tetrahedral shape. In dichloromethane, the bond angles are slightly different, leading to a distorted tetrahedral shape.

What other factors can affect bond angles in molecules?

Bond angles can also be influenced by the presence of lone pairs of electrons, which can create additional repulsion and alter the bond angles. Additionally, the presence of double or triple bonds can also affect the bond angles in a molecule.

How are bond angles in molecules determined experimentally?

The most common method for determining bond angles in molecules is through X-ray crystallography, where the positions of atoms in a crystal can be determined by measuring the diffraction of X-rays. Other techniques such as nuclear magnetic resonance (NMR) spectroscopy and infrared (IR) spectroscopy can also provide information about bond angles in molecules.

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