Dichloromethane (DCM), also described as methylene chloride, is an organic molecule. This is generally used as a solvent in most organic reactions due to its polarity. Students generally ask question “Is CH2Cl2 polar or nonpolar?” DCM has the chemical formula CH2Cl2. It contains two hydrogen and two chlorine atoms in a tetrahedral structure.
It’s a flammable, volatile, and colorless liquid substance with a sweet fragrance. Volcanoes, wetlands, and other oceanic outlets produce the compound naturally. Most of the dichloromethane supplied from the petrochemical industry.
Water is universally accepted polar solvent. But, Dichloromethane is not miscible with water. That means, It is not polar. Is CH2Cl2 polar or nonpolar?
It has a variety of applications due to its polarity, but it is most often found in the pharma and food industry. Here in this blog post, We can learn about the composition, molecular geometry, applications, is CH2Cl2 polar or nonpolar? and other chemical properties.
Because of its tetrahedral geometrical structure of dichloromethane and the disparity in electronegativity of the Carbon, Hydrogen, and Chlorine atoms in the molecule. Thus, CH2Cl2 is a polar molecule with specific dipole moment value .
This creates a dipole moment polarity through the C-Cl and C-H bonds, resulting in a net 1.67 D dipole moment for the whole molecule of CH2Cl2.
CH2Cl2 Lewis structure
The lewis structure is critical for understanding the properties and structure of every chemical compound, including organic compounds. Initially, the Lewis structure implemented inorganic compounds to fulfills the octet rule. But later, the same used in the organic molecules also.
Lewis structure is a theory based on the octet rule that aids in understanding the structure and chemical stability of any given compound. A molecule must have eight electrons in its outer shell to be inert or stable as Nobel atoms in the periodic table, according to the octet law.
One molecule of Carbon, two atoms of Hydrogen, and two atoms of Chlorine in tetrahedral geometry make up this complex in a structural arrangement.
It is important to determine the number of valence electrons in the compound in order to determine the Lewis structure. The number of electrons in each atom’s outer shell in a compound is known as valence electrons.
These electrons comprise both those that participate in the bond formation of molecule and those that do not. Bonding pairs of electrons are the electrons that are active in the chemical bond forming of any molecule.
Lone pairs of electrons or non-bonding pairs of electrons are those that do not take part in the formation of covalent bonds. These lone pairs of electrons always stay away from out of the plane of the molecule.
Lone pairs of electron of molecule undergoes in specific types of interaction. This types of interaction called lone pair lone pair, dipole dipole, and hydrogen bonding interaction.
CH2Cl2 Lewis structure calculation
The bonds are represented by line in drawing or dots, and the valence electrons are represented by dots in the Lewis structure. Carbon and hydrogen atoms are less electronegative than chlorine atoms in CH2Cl2. Calculate the cumulative number of valence electrons in Dichloromethane to better explain the Lewis structure.
Carbon has four valence electrons, Hydrogen has one valence electron, and Chlorine, like all other halogens, has seven in their outer shell orbitals.
Total number of Valence electrons = 4( valence electron of carbon) + 2*1( valence electron of Hydrogen)+ 2*7 (valence electron of chlorine)
= 20 (Total Valence electron of CH2Cl2)
The compound has twenty valence electrons and four bonds are formed in a tetrahedral geometry. Both Hydrogen and Chlorine atoms form set of two bonds with the central carbon atom.
As a result of this, the bond is formed by four valence electrons of Carbon in the center of tetrahedral geometry, two electrons of two Hydrogen atoms, and two electrons of two Chlorine atoms.
Hybridization of Dichloromethane (CH2Cl2)
Owing to the exchange of electrons between central carbon, two hydrogen, and two chlorine atoms. The orbitals of two or more atoms converge as they form a covalent bond. This is called the hybridization of atomic orbitals to form molecular orbitals.
Hybrid orbitals are orbitals that have overlapping orbitals with the central carbon atom. In dichloromethane (CH2Cl2), the formation of chemical bonds are covalent bonds in nature. If the molecule forms all four bonds in this molecule, the central carbon atom is hybridized.
Bonds are formed by an electron from the 22 sigma orbitals and three other electrons from the 2p sigma orbitals. As a result, the carbon atom hybridization in CH2Cl2 is sp3.
Preparation of Dichloromethane (CH2Cl2)
Methyl chloride or Dichloromethane is mostly emitted by industrial emissions to the environment. It’s made by heating methane to 400–500 degrees Celsius and treating it with chlorine gas.
The chemical reactions that occur during the formation of CH2Cl2 in industry are mentioned below.
CH4 + Cl2 —–400 to 500——–> CH3Cl + HCl
CH3Cl + Cl2 ———400 to 500——> CH2Cl2 + HCl
In the above said reaction, methane first converted into methylmonochloride with the elimination of hydrochloric gas. Further, methylmonochloride undergoes a reaction with chlorine gas and forms Dichloromethane. let’s see the molecular geometry of dichloromethane.
Molecular Geometry of Dichloromethane (CH2Cl2)
Understanding a compound’s molecular geometry is relatively simple in the organic molecules as compared with inorganic molecules. In the organic chemistry, the Carbon atom is the central figure in all molecular skeletons.
Organic molecules mostly form covalent bonds. In some cases, organic molecule forms coordination bond with metal atoms or ions.
Lewis structure is possible with organic molecules also. Lewis structure gives better understanding of dichloromethane molecules. It is dotted structure around central carbon atom.
Dichloromethane (CH2Cl2) molecules are structured such that the Carbon atom is in the centre of the molecular tetrahedral geometry, one Hydrogen atom is to the right, and the other is to the left of the central atom.
Similarly, one chlorine atom is to the right of Carbon central tetrahedral geometry, while the other chlorine atom is in the core central carbon atom’s downward place.
The molecular geometry of Dichloromethane becomes tetrahedral geometry when the hybridization is sp3.
Is CH2Cl2 polar or nonpolar Molecules?
There are a few key points in the subtopic of dichloromethane that we will explore below in order to assess and differentiate the polar or nonpolar existence of a CH2Cl2 molecule.
Let’s start with a basic understanding of polar and nonpolar molecules. Is CH2Cl2 polar or nonpolar molecule?
In general definition, molecules with an unequal proportion of mutual sharing of electrons in the covalent bond are known as polar molecules. This means that the electronegativity of atoms plays a very important role in the polarity of the molecules.
Every atom in the periodic table possesses a different electronegativity value. It is not an exact value. This value extracted from comparison with a hydrogen atom. This varying behavior of the electronegative value of atoms creates very interesting polarity properties in the molecules.
The higher electronegative value atom pulls the mutual sharing electrons to its side along the covalent bond, gaining a partial negative charge on it, while the other atom receives a partial positive charge on it.
This gaining and losing of electrons along the covalent bond of the molecule induce molecular interaction in different phases of matter.
This difference in electronegativity of atoms creates a net dipole moment around the covalent bond of the CH2Cl2 molecule, causing CH2Cl2 to become polar.
As it comes to the molecular geometry of the CH2Cl2 molecule, the shape of polar molecules is usually symmetrical or twisted in nature due to polarity in the covalent bond.
The electronegativity difference between any atoms of polar molecules is 0.5 to 1.6, according to most literature. If the electronegativity gap is less than 0.5 or greater than 1.6, the bond is nonpolar. This is the general definition. But it can be applied in all molecules.
When two atoms have differing electronegativity values along with the covalent bond, the atom with the higher electronegativity draws the mutual sharing electrons closer to its side along with the covalent bond of the CH2Cl2 molecule.
As a result of this, the atom with the most electronegativity of chlorine atom has a greater electron density than other atoms in the CH2Cl2 molecule.
The degree of polarity varies by atom in the molecules; some are barely polar, while others are extremely polar in nature. It is purely depends on electronegativity of atoms in the molecule.
Nonpolar Molecules: Nonpolar molecules are those in which all of the atoms share an equal amount of mutual sharing of electrons along with the covalent bond of the molecule.
In such atoms in the molecule, no opposite poles form. These molecules have a symmetrical structure with no twisted or no polarised form in their geometry.
It’s likely that a nonpolar molecule has polar bonds, but the dipoles of these polar bonds balance or cancels each other out due to the symmetric geometrical structure.
It simply means that nonpolar molecules are formed as atoms share the electron alongpolar bond structure in which their electric charges cancel out.
Nonpolar molecules include BeCl2, CO2, and others. You should look at the explanation for BeCl2’s non-polarity.
Nonpolar are both inert gases (Monoatomic gases), heteromnuclear atom with symmetrical geometry and homonuclear diatomic molecules in the .
It is advisable for all the students, please review basic chemistry terms such as electronegativity, dipole moment, symmetry, and structure of the molecule in order to define the polarity and non-polarity of the molecular compounds.
Polarity of Dichloromethane (CH2Cl2)
The polarity of any compound is determined by the number of lone pairs of electrons and the compound’s molecular geometrical symmetry.
It is also determined by the electronegativity of the molecules involved in the compound’s formation. Since the hydrogen atoms are less electronegative than the chlorine atoms, the compound has a net dipole moment. CH2Cl2 is a polar molecule
Dichloromethane is therefore polar molecule due to the asymmetric structure of the bonded pairs in their molecular geometry.
Physical Properties of CH2Cl2
CH2Cl2 molecule is a different type of organic molecule. It is used as a solvent in most of the chemical and pharma industries. It will be good to look at their physical and chemical properties
|Property of the CH2Cl2 molecule||Experimental values of CH2Cl2 molecule|
|The density of Dichloromethane (DCM)||1.3226 g/cm3|
|The molecular weight of Dichloromethane (DCM)||84.93 g/mol|
|The boiling point of Dichloromethane (DCM)||39.60C|
|The melting point of Dichloromethane (DCM)||-97.60C|
Important terms of CH2Cl2 Chemistry
Electronegativity of CH2Cl2 molecule:
The term electronegativity refers to an atom’s ability to draw an electron pair to its side along the covalent bond of C-Cl and C-H of CH2Cl2 molecule.
This gives a clearer picture of the electronic structure of atoms in a CH2Cl2 molecule .
The higher the value of chlorine atom’s electronegativity in CH2Cl2 molecule, the stronger its affinity on electrons is.
With more electronegativities of chlorine atom in CH2Cl2 molecule, electrons in a polar bond are shifted closer to the electronegative chlorine atom in CH2Cl2 molecule.
As a consequence, a partially negative charge is added to the higher electronegative chlorine atom in CH2Cl2 molecule. The electron density distribution around the CH2Cl2 molecule becomes more polarised as the variation in electronegativity grows towards it.
The electronegativity of an element in the periodic table increases from left to right and decreases down a group of elements.
The electronegativity of the connecting atoms is used to establish the polarity of the bond.
The electronegativity of all bonding atoms in dichloromethane is as follows:
Hydrogen=2.2, carbon=2.5 and chlorine=3.1.
Difference in electronegativity between C-H=0.3 and C-Cl=0.6. It proves that CH2Cl2 is polar, but a mild polar, since the electronegativity difference between them is very slight.
As a result, the elements on the right appear to have the largest electronegativities element in the periodic table, making the halogen group the most electronegative in nature. Chlorine comes on the right side of the periodic table with a higher electronegative value.
Metals have lower electronegativities than other elements, and group 1 metals have the lowest. The hydrogen atom is most electropositive in nature.
Dipole moment of CH2Cl2:
A dipole moment is a second critical element in determining the polarity of a chemical bond between two atoms or more atoms in a molecule. CH2Cl2 molecule has two C-H and two C-Cl bonds. The bond polarity of C-H is different from the C-Cl bond of the CH2Cl2 molecule.
It determines how well negative and positive charges are separated in a CH2Cl2 molecule. In Chlorine atom gets more partial negative charge. In hydrogen atom gets more partial positive charge.
The dipole moment of a molecule is defined as the product of the charge magnitude on atoms and the distance between their centres in mathematics. C-H bond shows more negative charge on carbon atom and more positive on hydrogen atom.
C-Cl bond shows in the opposite manner, more negative charge on Cl atom and more positive on Carbon atom in the CH2Cl2 molecule.
The shape of the CH2Cl2 molecule:
The shape of a molecule is another element that decides the polarity of the CH2Cl2 molecule. The overall centre of overlapping positive and negative charges determines whether a complex molecule is CH2Cl2 polar or non-polar.
If a molecule is fully symmetric, the dipole moments on each molecule cancel out, resulting in a nonpolar molecule.
A molecule is said to be polar if the structure of a molecule is not symmetrical geometry. CH2Cl2 is a polar molecule in nature.
Uses of Dichloromethane (CH2Cl2):
Dichloromethane(DCM) is used as a stain remover solvent and a cleaner in the food industry.
It may also be used as a degreaser in the grease and oil industries.
It’s used as a cleaner to strip paint or varnish coatings from a number of surfaces and for bathtub refinishing.
It’s used to spray paint and insecticides in the aerosol industry.
The most common use is to decaffeinate coffee beans and tea leaves in the food industry.
It’s used in the food and beverage industry to process spices and other flavorings agents.
In the pharmaceutical industry, it is used as a solvent.
CH2Cl2 is used to extract toxins from plants in order to make contraceptives, supplements, and antibiotics.
CH2Cl2 disinfects medical equipment without corroding them or allowing them to overheat.
As an ink diluter, CH2Cl2 is used.
Dichloromethane(CH2Cl2) is used to degrease metal surfaces, airplane parts, railroad tracks, as well as other equipment.
In pharma industry, It is used as a solvent in many of the organic synthetical reactions.
It is used to remove gaskets and prepare metal parts for new gaskets in automotive products.
The vapour of CH2Cl2 is used in the automotive industry to strip oils and grease from car transistor components.
Synthetic fibres and photographic films are both made of dichloromethane.
It is used as a solvent in column chromatography to purifies the organic drug molecules.
CH2Cl2 is also used to create aerosol formulations in the combination with silicon.
Hazards of using Dichloromethane (CH2Cl2) in Industries:
Since CH2Cl2 is extremely flammable nature, it poses a serious risk of inhalation. As a result of the gas’s acute absorption, prolonged exposure to Dichloromethane (DCM) can induce dizziness, nausea, headaches, and other symptoms in the physiology of humans.
Dichloromethane (DCM) is metabolized in the body as carbon monoxide, which can cause carbon monoxide poisoning. Carbon monoxide (CO) binds very stronger with the hemoglobin of blood as compared with the oxygen molecule (O2). It will take a person initial dizziness and prolong exposer leads to coma or unconscious death.
It has also been related to many forms of cancer, making it a carcinogenic compound.
When inhaled for a prolonged amount of time, the compound can induce irregular heart rhythms and heart attacks in people with heart problems.
It may also irritate the nose and throat in some situations along with other volatile solvents.
It is noncombustible, but it releases poisonous phosgene gases(COCl2) at high temperatures.
It causes a disturbance in the nervous system.
The eyes, throat, and nose get irritated.
Key points to check the polarity of CH2Cl2
Through comparing the electronegativity of the chlorine atoms in the bonding of CH2CL2 molecule, the degree of polarity can be measured by used above said calculation.
The structure and geometry of the CH2Cl2 molecules can be used to determine the polarity of it. Dipole moments of C-H and C-Cl bond are also important in determining a CH2Cl2 polarity.
Precautions to handle CH2Cl2
- Wear an apron and protective clothing with full sleeves before using CH2Cl2.
- Wear lab boots that cover the whole foot.
- Wear your PPE kit, goggles, and safety gloves at all times due to the handle CH2Cl2.
- Make sure you’re working in a well-ventilated environment in the chemical laboratory on the fumehood.
- It should be kept in a cold, under no direct sunlight exposer, dry place in tightly sealed and labeled containers because it is extremely volatile.
- And it should be kept away from metals, light, and any heat or ignition source. It is extremely high flammable in nature.
Concluding Remarks on CH2 Cl2 polarity
I hope you found this post on Dichloromethane (CH2Cl2) to be more informative. The CH2Cl2 molecule contains twenty valence electrons, eight of which are involved in bond forming. It has polarity and sp3 hybridization. DCM is a trigonal pyramidal molecule of tetrahedral molecular geometry.
C-H and C-Cl have dipole moments that do not cancel with each other. This makes the CH2Cl2 molecule polar in nature. Over prolong exposure to this compound leads to more health related problems.
FAQ on CH2Cl2 polar or nonpolar
Is CCl2H2 polar or nonpolar?
Yes, CCl2H2 is a polar compound. Since Cl is more electronegative than H, the electrons would be tugged more. Unlike carbon tetrachloride, the net dipole moment will not cancel out in this situation.
How is ch2cl2 polar
Because of its tetrahedral geometrical structure and the disparity in electronegativity of the Carbon, Hydrogen, and Chlorine atoms, CH2Cl2 is a polar molecule. This creates a dipole moment through the C-Cl and C-H bonds, resulting in a net 1.67 D dipole moment for the whole molecule.
The polarity of the molecules
The polarity of the molecules are listed as follows
- Polarity of BeCl2
- Polarity of SF4
- Polarity of CH2Cl2
- Polarity of NH3
- Polarity of XeF4
- Polarity of BF3
- Polarity of NH4+
- Polarity of CHCl3
- Polarity of BrF3
- Polarity of BrF5
- Polarity of SO3
- Polarity of SCl2
- Polarity of PCl3
- Polarity of H2S
- Polarity of NO2+
- Polarity of HBr
- Polarity of HCl
- Polarity of CH3F
- Polarity of SO2
- Polarity of CH4
Lewis Structure and Molecular Geometry
Lewis structure and molecular geometry of molecules are listed below
- CH4 Lewis structure and CH4 Molecular geometry
- BeCl2 Lewis Structure and BeCl2 Molecular geometry
- SF4 Lewis Structure and SF4 Molecular geometry
- CH2Cl2 Lewis Structure and CH2Cl2 Molecular geometry
- NH3 Lewis Structure and NH3 Molecular geometry
- XeF4 Lewis Structure and XeF4 Molecular geometry
- BF3 Lewis Structure and BF3 Molecular geometry
- NH4+ Lewis Structure and NH4+ Molecular geometry
- CHCl3 Lewis Structure and CHCl3 Molecular geometry
- BrF3 Lewis Structure and BrF3 Molecular geometry
- BrF5 Lewis Structure and BrF5 Molecular geometry
- SO3 Lewis Structure and SO3 Molecular geometry
- SCl2 Lewis structure and SCl2 Molecular Geometry
- PCl3 Lewis structure and PCl3 Molecular Geometry
- H2S Lewis structure and H2S Molecular Geometry