Chlorinated hydrocarbons are generally used as a solvent in the chemistry laboratory. Methyl trichloride or trichloromethane is falling in the same family with the chemical formula of CHCl3. This molecule has three C-Cl bonds, Cl atom is having a higher electronegativity value. The student used to ask ” is ChCl3 polar or nonpolar?”, “CHCl3 Lewis structure”, “CHCl3 molecular geometry”, and “polarity of CHCl3”.
In this blog post, we try to answer all the above said questions in a detailed manner. It is a colorless organic liquid. CHCl3 is not miscible with water and creates a separate organic interracial layer. It gives a sweet pleasant aroma and vaporizes very easily.
Is CHCl3 polar or nonpolar molecule, then? Because of its tetrahedral molecular geometry structure and the difference in electronegativity value of carbon(C), hydrogen(H), and Chlorine(Cl), CHCl3 is polar. Chlorine atoms are more electronegativity value than carbon and hydrogen atoms, and they are located at three of the pyramid’s vertices, pulling the negative charge in their direction, resulting in a polar molecule with a downward dipole.
Is CH3Cl Polar or Nonpolar molecule:
Polarity is a property that is found in CHCl3 molecule that has positive and negative charges separated in them. This occurs when the electronegativity value of the atoms in the CHCl3 molecule varies significantly. It is important to decide whether the CHCl3 molecule is polar because polarity influences other physical properties. In this blog from our previous post, we will look at the polarity of the CH2Cl2 molecule and find out if the molecule is polar or not.
Chloroform (CHCl3) is a highly flammable substance that reacts with light and air to produce toxic gas. It is known as carbonyl chloride(COCl2), also known as phosgene gas. During World War II, this gas was used to eliminate the people.
As a result of this, chloroform(CHCl3) should be kept in a dark room with almost nil light penetration, tightly closed bottles up to the brim. It won’t allow the gas to escape from the bottle. It’s often regarded as a strong anesthetic for some surgical applications.
CHCl3 has a molecular mass of 119.37 g/mol. It is possible to quantify it as follows:
Molecular mass of Chloroform(CHCl3) = 1* 12(atomic mass of C) + 1 * 1(atomic mass oh H) + 3 * 35.4(atomic mass of Cl) =119.7 g/molcalculation of molecular weight of CHCl3 molecule
CHCl3 has one carbon central atom, one hydrogen atom, and three chlorine atoms in its surrounding tetrahedral geometry with the mentioned chemical composition. CHCl3 molecule has a tetrahedral geometry structure, with hydrogen at the top and chlorine atoms at three vertices in the pyramid’s center with the carbon atom.
The core central atom in the CHCl3 molecule tetrahedral structure is carbon, which is surrounded by one hydrogen and three chlorine atoms. One C-H and three C-Cl bonds are single covalent, and electronic configuration stabilizes all atoms in the CHCl3 molecule.
The electronegativity value of atoms in the CHCl3 molecule plays a very important role in the polarity of the molecule. There are two types of dipole moment or polarity of the bonds in the molecule and the dipole moment of the entire molecule. As a result, the final entire dipole moment of the CHCl3 molecule decides whether the molecule is polar or nonpolar in nature.
The hydrogen atom has an electronegativity value of 2.2, the chlorine atom has a value of 3.16, and the carbon atom has a value of 2.55. The difference of electronegativity value of C-H bond and C-Cl bond of CHCl3 molecule can be calculated as follows
Hydrogen atom electronegativity = 2.2
Chlorine atom electronegativity = 3.16
Carbon atom electronegativity = 2.55
Electronegativity value difference of C-H bond = 2.55 – 2.2 = 0.35
Electronegativity value difference of C-Cl bond = 3.16 – 2.55 = 0.61Electronegativity value difference calculation
As a result, the CHCl3 molecule has polar one C-H and three C-Cl bonds. The carbon atom pulls the electrons to its side along the C-H bond, while chlorine pulls the electrons to its side along the C-Cl bond because of chlorine atoms. This is due to, chlorine atom has electronegative than the carbon atom.
The charge distribution on the hydrogen, carbon, and chlorine atoms of the CHCl3 molecule is unequal due to unequal electronegativity value and tetrahedral geometry structure form.
Preparation of Chloroform:
Chloroform is synthesised by photo chemical reaction with methane and chlorine gas. The photochemical reaction are written as follows
CH4 + Cl2 ——-hv (light energy) ——-> CH3Cl + HCl [Chloromethane]
CH3Cl + Cl2 —— hv (light energy)—> CH2Cl2 + HCl [dichloromethane]
CH2Cl2 + Cl2 —– hv(light energy) —–> CHCl3 + HCl [Trichloromethane or chloroform]
Methane is called natural gas. First, methane gas reacted with chlorine gas in the presence of ultraviolet(UV-light). It undergoes a free radical reaction. UV light dissociates the chlorine molecules as free radical chlorine. Methane gas dissociates as methyl radicals and hydrogen radicals.
Free radicals are very reactive chemical species. It undergoes a very fast chemical reaction. methyl and chlorine free radicals combine to form monochloromethane. Then further undergoes reaction, chloromethane reacted further with chlorine free radical and forms dichloromethane.
Dichloromethane is reacted with chlorine free radical and forms chloroform. In this reaction, the formation of hydrochloric acid gas is also there. This is another one method for the preparation of hydrochloric acid.
Polar versus Nonpolar Molecule
CHCl3 molecule polarity can be determined by considering a number of variables. Covalently bonded molecules can be both polar and nonpolar in nature. Let’s look at the distinctions between polar and nonpolar molecules in a detailed manner.
Polar Molecules: Polar molecules are those whose dipole moment value is greater than zero, indicating that they have a permanent resultant dipole moment in the entire molecule. More detailed studies and explanation about polar vs nonpolar molecule is available in our previous post.
The charge distribution in these polar molecules is not uniform around the molecule’s electron cloud. Atoms in these molecules have different electronegativity values and having differences in electronegativity as calculated above.
Where the electronegativity value of two atoms differs, the covalent bond formed between them appears to be polar. Here, the covalent bond is polar in nature. Polar molecules’ geometry is skewed or distorted, i.e. asymmetric, resulting in irregular charge distribution.
The dipole moment of these types of molecules is always zero. Otherwise, the molecule has a permanent dipole moment in its covalent chemical bond. But it may some have canceled each other in the molecular symmetric structure. The electric charge distribution in these molecules is uniform.
The electronegativity value of the atoms in these molecules is identical, implying that they have the same effect on the bound electron pair. When two atoms have identical electronegativity values, their covalent bond appears to be nonpolar. They can be canceled by each other. Finally, the molecule becomes nonpolar in nature.
In other cases, the electronegativity value of the atoms in the molecule is not identical. Then the difference of electronegativity value of atoms is different. But due to the perfect symmetrical structure of the molecule, the dipole moment of the individual bond canceled to each other. Finally, the molecule becomes nonpolar.
CHCl3 Lewis Structure, molecular geometry, and polarity:
There is a close relationship between the electron structure of the molecule and its polarity. Lewis structure is not only applicable to simple inorganic compounds. It is applicable for organic molecules. In the organic molecule, the central skeleton of the molecule is a tetrahedral structure. CHCl3 molecule is a very simple tetrahedral molecule.
Lewis structure of molecule drawn by using dot structure. The entire diagram uses only the valence electron as a dot in the molecular skeleton. Lewis structure is not considering the core shell electron. It is only accountable for the valence electron of the molecule.
CHCl3 molecule has one central carbon, one hydrogen atom, and three chlorine atom. Carbon is the central atom of the CHCl3 molecule in its tetrahedral geometry. carbon has four valence electrons in its outermost shell. First around the carbon atom put four dots as a representation of an electron in all four directions. One hydrogen atom with only one electron in its outermost valence shell.
The hydrogen atom goes in the top of the tetrahedral geometry. This is due to the low electronegativity value of hydrogen as compared with carbon and chlorine atoms. Halogen atoms are a high electronegativity value in the periodic table. The chlorine atom has seven valence electrons in the valence outermost shell. It needs one more electron to achieve octet rule configuration. To see more details about the octet rule, please visit in our previous post.
Three chlorine atoms paired with a central carbon atom in the tetrahedral geometry. Carbon surrounded with eight electrons, three chlorine atoms surrounded with eight electrons, and only hydrogen atoms paired with two electrons. Eight electron octet rule stabilization is not possible in the hydrogen atom of CHCl3.
Polarity of CHCl3
Trichloromethane, with the chemical formula CHCl3, has one carbon atom in the middle, three chlorine atoms, and one hydrogen atom. Carbon takes a central role since it is less electronegative than Chlorine, and the majority of the atoms are grouped around it in all organic molecular geometry.
CHCl3 molecule’s Lewis dot structure shown above in that there are no lone pairs of electrons in its structure. Carbon shares four electrons with the other atoms in the molecule, completing the octet. The molecule has a tetrahedral shape since all three atoms have 26 valence electrons that participate in bond formation.
Valence electron from carbon = 4
Valence electron from hydrogen = 1
valence electron from three chlorine = 3 * 7 = 21Valence electron in CHCl3
Assume you’re comparing the electronegative value of carbon and chlorine. In that case, you will find out that the chlorine atom is more electronegative than the carbon atom as it is closer to Flouirne on the periodic table. So there will be a dipole moment between Chlorine and Carbon atom. As Chlorine has more electronegativity, it tries to pull the electrons on its side. This dipole moment results in the unequal distribution of charges on Carbon and Chlorine covalent bonds. Thus C-Cl bond is considered to be polar.
When it comes to the bond between Carbon and Hydrogen atoms, the difference in the electronegativities of both these atoms is relatively small. Already, we discussed in the above section. Due to which the C-H bond is considered nonpolar.
As a result, the three C-Cl bonds is called the polar bond in the CHCl3 molecule. The disparity in electronegativities between Carbon and Hydrogen atoms is relatively small when it comes to the bond between these two atoms. As a result, the C-H bond is regarded as nonpolar in nature.
However, since the three Chlorine atoms have partial negative charges and a net dipole moment, CHCl3 is a polar molecule.
How to check the polarity of the CHCl3 molecule?
If you want to verify CHCl3 molecule’s polarity, make a list of the following points.
Electronegativity of CHCl3 molecule :
The term electronegativity refers to the chlorine atom’s ability to draw a bound electron pair to one of its sides in a CHCl3 molecule. The stronger the chlorine atom’s electronegativity, the stronger it draws the electrons towards its side.
When the electronegativity value of carbon and chlorine atoms forming a covalent C-Cl bond differs, the C-Cl bond is more likely to be polar. The difference in electronegativity is directly proportional to the polarity of a covalent C-Cl bond.
To determine the degree of polarity of the CHCl3 molecule, you must record the electronegativity of both carbon and chlorine atoms.
Geometrical shape of CHCl3 molecule:
The molecular geometry shape of the CHCl3 molecule plays an important role in determining its polarity. We already molecular geometry of CHCl3 in a detailed manner as mentioned above.
Dipole Moment of CHCl3 molecule:
The polarity of a covalent C-Cl bond is directly proportional to the difference in electronegativity value of carbon and chlorine atoms in the CHCl3 molecule. You must record and compare the electronegativity value of both carbon and chlorine atoms to assess the degree of polarity in the CHCl3 molecules.
The polarity of CHCl3 molecule is determined in part by its geometrical shape.
Calculation of dipole moment of C-H bond in CH3molecule:
Q(c-h)= charge distribution between Carbon and hydrogen atom
R(c-h)= Bond distance between carbon and hydrogen atom
D(c-h)= Dipole moment of C-H bond
Calculation of dipole moment of C-Cl bond in CH3molecule (three C-Cl bond):
Q(c-cl)= charge distribution between Carbon and chlorine atom
R(c-cl)= Bond distance between carbon and chlorine atom
D(c-cl)= Dipole moment of C-Cl bond
D(c-cl)= R(c-cl)*Q(c-cl)Dipole moment calculation of CHCl3
The net dipole moment value of trichloromethane (CHCl3) is 1.15 D.
Why is the CHCl3 Polar?
Because of the reasons listed below, chloroform or trichloromethane (CHCl3) molecule is polar.
- The polarity of CHCl3 molecules refers to the presence of two opposing poles, i.e., negative and positive poles in the chlorine and carbon atom.
- The chlorine atom with the highest strength of negative charge becomes the negative pole in a chemical covalent C-Cl bond, while another carbon central atom becomes the positive pole.
- Since the chlorine atom in the CHCl3 molecule is more electronegative than hydrogen and carbon, its electron density rises and it becomes a negative pole in the CHCl3 molecule, whereas hydrogen and carbon are positive poles of the CHCl3 molecule.
- CHCl3 molecule is indeed tetrahedral geometry in shape, with carbon at the central, hydrogen atom in the top of tetrahedral, and chlorine atoms at three of the pyramid’s vertices at the bottom.
As a result of the above discussion, all three chlorine atoms in the CHCl3 molecule give a net dipole in a downward direction of tetrahedral geometry. Therefore, chloroform (CHCl3) is a polar solvent. It is commonly used as a solvent in organic synthesis laboratories.
Physical properties of Trichloromethane(CHCl3)
Trichloromethane(CHCl3), also known as methyl trichloride, is an odorless and flammable liquid. It’s a natural substance and synthetical also manufactured in the industries. It is a colorless liquid with a mildly sweet odor that is only detectable at a certain concentration where it is a natural anesthetic agent.
|Name of the molecule||Trichloromethane|
|Molecular weight||119.7 g/mol|
|Boiling point||61.2 °C|
|Dipole moment||1.15 D|
|Melting point||-63.5 °C|
Properties of CHCl3
The important properties of CHCl3 are listed below,
- It is a colorless liquid with a sweet odor at room temperature with a boiling point at 61.2 °C and a melting point at -63.5 °C.
- It has a specific density of 1.489 g/cm3 at 25 degrees Celsius temperature.
- It has a melting point of -63.5 degrees Celsius (82.3 degrees Fahrenheit) and a boiling point of 61.15 degrees Celsius (142.07 degrees Fahrenheit).
- vapor pressure of CHCl3 is 1.7 × 10 2 mmHg
- The surface tension of CHCl3 is 2.7 × 10–2 J/m2
- The viscosity of CHCl3 is 5.8 × 10–4 Kg/m*S
- It is not soluble in water. It is very less soluble in water. Its solubility in water is 8.09 g of CHCl3/1000ml of water. The percentage of solubility is very less.
- CHCl3 has a vapor pressure of 25.9 kPa at 25 °C. It easily vaporizes at room temperature.
Uses of TriChloromethane(CHCl3)
The uses of chloroform(CHCl3) is listed as below,
- Trichloromethane was once used as a solvent in organic synthesis
- In the pharmaceutical industry, methyl chloride is also used as a methylating and chlorinating agent for methylation reactions.
- CHCl3 can also be used as a herbicide and a local anesthetic in medical treatment.
- At low temperatures, the CHCl3 molecule is often used as a solvent carrier in the polymerization process for many polymer pigment industries.
- It’s also used as an oil, grease, and resin extractant along with hexane solvent.
- Chloroform(CHCl3) can also be used to make refrigerant gases like Freon R-22. Electronic devices, such as refrigerators and air conditioners, use this gas and liquid. But it was phased out after it was discovered to have adverse effects.
- Chloroform(CHCl3) can dissolve alkaloids, fluoride, fats, and other substances. It is used in the purification of natural products. It is used as a solvent in Column chromatography to purify organic molecules.
- It’s used in medicine as a local anesthetic during surgical procedures. On exposure to air and light with intense heat, chloroform produces a very poisonous gas known as phosgene(COCl2).
Concluding Remarks on CHCl3
The electronegativity of the CHCl3 molecule is an important factor in determining whether a CHCl3 molecule is polar or nonpolar. Since three chlorine atoms have a higher electronegativity than the central carbon and top terminal hydrogen atoms, it has a partial negative charge, while the hydrogen atoms have partial positive charges in the te3trahedral geometry. Chloromethane is a polar molecule because its net dipole moment is not zero. The net dipole moment of chloroform is 1.15 D.
FAQ on “Is CHCl3 polar or nonpolar?”
Why is CHCl3 a polar molecule?
Chlorine(Cl) atom is more electronegative value than carbon(C) atom because it is closer to Fluorine(F) atom on the Periodic Table; hence, a dipole arrow is drawn from C to Cl. The CHCl3 possesses a net dipole because the three C-Cl bonds are polar, hence CHCl3 is polar.
Is CHCl3 polar or nonpolar or ionic?
CHCl3 is a polar molecule. Because of its tetrahedral molecular geometry shape and the difference in electronegativity value of carbon(C), hydrogen(H), and chlorine(Cl), CHCl3 is polar molecule.
Is CHCl3 a nonpolar solvent?
CHCl3 is polar molecule. But it is a nonpolar solvent due to its low dielectric constant value. In the organic solvent chart, it stays near at the bottom of nonpolar solvent catogetry.
Is CHCl3 more polar than water?
Water is higher polar molecule with high dielectric constant value. If you compare CHCl3 with water, then water is polar. In this case, CHCl3 is nonpolar as compare with water. If you compare CHCl3 with aprotic organic solvents, then it is highly polar in nature.
It is purely depends on your comparison with what?
Why is CHCl3 more polar than CCl4?
The dipole moment of CCl4 moleciule is zero. Although each four C-Cl bonds are fairly polar in the nature, the CCl4 molecule’s tetrahedral structure causes the four C-Cl bond dipoles to balance and cancelled out. CHCl3 is more soluble in water as compare with CCl4 .Because polar water molecules interact better with polar CHCl3 molecules than non-polar CCl4 molecules. This types of interaction are called polar-polar interaction between the molecules.
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