CH2Cl2 Intermolecular Forces:Detailed Facts


In this article we will discuss about the ch2cl2 intermolecular forces : detailed facts .

CH2Cl2 is the chemical formula for dichloromethane. It also has some synonyms like known as methylene dichloride or methylene chloride. Methylne dichloride (CH2Cl2) is a volatile liquid with no color and having some sweet odour. It is mostly used as a solvent in chemical reactions.

It is insoluble in water but soluble in most of the organic solvents. It is used in polyurethane foams as blowing agent and also used as propellant in aerosol spray. Here, we are discussing about the ch2cl2 intermolecular forces and detailed facts.

Intermolecular forces in CH2Cl2

Intermolecular Forces:  Intermolecular forces can forms within any two molecules or chemical compound. It is a weak bond forms within the molecules. In intermolecular forces attractive and repulsive forces can cause within the two molecules of the substance. Due to intermolecular forces physical properties of any substance get determine like density, boiling point, enthalpies of fusion and vaporization and melting point.

The CH2Cl2 molecule is consists of total three elements i.e. carbon, hydrogen and chlorine atoms. In this molecule the central C atom gets joined to two hydrogen atoms and two chlorine atoms. So, the central C atom has four outer bonding atoms attached to it. Hence as per VSEPR module, it has AX4 generic formula and has tetrahedral geometry. In tetrahedral geometry the arrangement of atoms is asymmetrical due to which the CH2Cl2 is being an polar molecule.

Also the electronegativity of hydrogen atom is 2.2, electronegativity of carbon atom is 2.55 and electronegativity of Chlorine atom is 3.15. So, the electronegativity difference between central C atom and Cl atom is 0.6 which is greater than 0.4 according to Pauling’s rule. Due to the higher electronegativity difference between the C and Cl atom the polar bond is formed which makes the CH2Cl2 molecule polar in nature.

	ch2cl2 intermolecular forces
CH2Cl2 structure with intermolecular bonds wikipedia

What types of intermolecular forces are found in CH2Cl2?

Dichloromethane (CH2Cl2) has two types of intermolecular forces i.e. dipole – dipole intermolecular forces and London dispersion forces. CH2Cl2 is a polar compound. The CH2Cl2 molecule has tetrahedral geometry which is not symmetrical. That is the CH2Cl2 molecule has asymmetrical arrangement of C, H and Cl atoms.

 The electronegativity of chlorine atom is much greater than hydrogen atom also the electronegativity difference is also high due to which the electron density more goes towards the chlorine atom than hydrogen atom. Due to which the dipole moment is created within the CH2Cl2 molecule.

This dipole moment on atoms of CH2Cl2 molecule cannot cancel out each other as the geometry is asymmetrical. Hence, a partial positive charge creates on hydrogen atom and partial negative charge creates on chlorine atom of CH2Cl2 molecule. So, the permanent dipole creates on CH2Cl2 molecule.

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The attractive forces within polar molecules are known as dipole – dipole interactions. London forces or the dispersion forces are generated for the small distance and it is a weakest type of force. Due to the movement of electrons the London forces are generated and also cause the temporary negative and positive charge density.

CH2Cl2 strongest intermolecular forces

In ch2cl2 intermolecular forces, the dipole – induced – dipole interaction is the strongest intermolecular force within the CH2Cl2 molecule. In dipole – induced – dipole interaction the non – polar molecule or compound gets converted into induced dipole if the polar molecule is present nearby to the non – polar molecule.

The electronegativity difference between C and Cl atom is higher, so the dipole – dipole interaction creates within C and Cl atoms by creating partial negative charge on Cl and partial negative charge on C atoms. If the CH2Cl2 molecule gets reacted with non – polar molecule like benzene, toluene, hexane, pentane etc. it can cause strongest dipole – induced – dipole interaction.

Hence, when CH2Cl2 reacts with non – polar solvents like benzene, the strongest dipole – induced – dipole interaction force occurs due to which the benzene molecule which is non- polar in nature gets converted into a polar molecule like diphenyl methane.

CH2Cl2 in H2O intermolecular forces

CH2Cl is a polar molecule and likewise water H2O is also a polar molecule, still they are not miscible with each other, because the water molecule is very much polar molecule in nature. If we mixed non – polar molecules in any aqueous solvents or water, they behaves as hydrophobic and all the non – polar molecules together aggregates and separates the water particles making two layers.

 CH2Cl2 is have more density than water, thus when we CH2Cl2 added in water the dichloromethane gets settle down at the lower side or bottom and water get up at upper part. Thus there also makes two layers of water and CH2Cl2. So, CH2Cl2 is very partially miscible or not miscible in water even if they both molecules are polar in nature.

Also, CH2Cl2 cannot form hydrogen bond with water because the chlorine atom present in CH2Cl2 is a large atom and it has its lone pair electrons present in diffuse orbitals. Due to which when CH2Cl2 reacts with water, chlorine atom covers a big area and hence chlorine does not have high electron cloud or charge density to behave like acceptor strong hydrogen bond with water. Thus there is no intermolecular force between CH2Cl2 and water.

CH2Cl2 in benzene (C6H6) intermolecular forces

CH2Cl2 (dichloromethane) is a polar solvent and benzene (C6H6) is a non – polar solvent. When the polar and non – polar solvent get mixed with each other, the non –  polar solvent molecules get aggregates together one side and polar solvent get separated from non – polar solvent which we can see from our eyes in a transparent beaker. Thus two layers get formed in the same solution.

When CH2Cl2 gets react with benzene (C6H6) in presence of anhydrous AlCl3, the diphenyl methane gets formed.  This reaction is known as Friedels – Crafts Reaction. When CH2Cl2 reacts with AlCl3 there is the formation of CH2+Cl ion with the removal of one chlorine atom. Further when CH2+Cl ion reacts with benzene there is the formation of C6H6+-CH2Cl ion.

There is the continue formation of polar molecules by creating partial positive and negative charges in the molecule. There is continued removal of chlorine atoms in this reaction for the formation of diphenyl methane (C6H6-CH2-C6H6). Total two chlorine atoms get removed from dichloro methane to form diphenyl methane. Thus dipole – induced – dipole intermolecular force is present in such polar and non – polar molecular interactions.

Conclusion

CH2Cl2 is an chemical formula dichloro methane. There are two types of intermolecular forces forund in CH2Cl2 molecule i.e. dipole – dipole intermolecular force and London dispersion force. It does not soluble in water and does not form hydrogen bonds. It is mixed with non – polar solvent like benzene and Friedel crafts reaction is occurs to form diphenyl methane in which dipole – induced – dipole intermolecular forces is present.

Darshana Fendarkar

Hi....I am Darshana Fendarkar, I have completed my Ph.D. from the University of Nagpur. My area of specialization is Inorganic Chemistry. I have an experience as a Chemist at Earthcare Pvt. Ltd. Also I have 2 years of experience in teaching. Currently, I am working with Lambdageek as a Subject Matter Expert. Let's connect through LinkedIn-https://www.linkedin.com/in/dr-darshana-fendarkar-00380540

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