Carbon tetrachloride is a polar molecule because it has a permanent dipole.
This means that one side of the molecule is positively charged and the other side is negatively charged.
These charges are intensified by the electron cloud distortion induced by the strong carbon-chlorine bond.
Is CCl4 Polar or Non-Polar? (Explained)
What is Carbon Tetrachloride?
Carbon tetrachloride is an inorganic compound with the chemical formula CCl4.
It is a colorless liquid with a mild, pleasant odor.
It is used as a solvent in organic synthesis and as a refrigerant.
Carbon tetrachloride is a common contaminant found near facilities that use chlorine-bearing chemicals.
It is formed by the photochemical decomposition of these organohalogens.
Since carbon tetrachloride has been identified as an ozone depletion agent, it no longer has routine applications.
However, it still finds limited use in certain niche applications.
The most common impurity of carbon tetrachloride, 1,1,2-Trichloroethane (TCA) has also been identified as an ozone depletion agent.
The main sources of TCA are Polychlorinated Biphenyls (PCBs) and related organochlorine compounds.
During the production process for Chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs), there are several means to eliminate TCA formation via removal or destruction.
These processes include hydrocarbon gas desulphurization, amine gas treating, thermal destruction, and adsorption or absorption onto activated carbon.
Unfortunately, some facilities have not taken advantage of these more environmentally friendly technologies, which have proven successful at the majority of CFC or HCFC plants worldwide.
This failure to implement the proper controls has created a significant global source of carbon tetrachloride and 1,1,2-trichloroethane.
Carbon tetrachloride was once used in fire extinguishers, as a precursor to refrigerants and as a cleaning agent for mineral oils and waxes.
It is currently employed for these purposes, but now it’s found primarily in chlorofluorocarbon-based fire suppression systems and air conditioning cleaning cycles.
Carbon tetrachloride was used in chemistry laboratories until the late 1980s, where it was commonly used to prepare extractions.
Preparing an organochlorine extraction involved scrubbing the inside of a separatory funnel with sodium hydroxide or potassium hydroxide, and then adding carbon tetrachloride to the base of the funnel.
This allowed organic compounds containing chlorine or bromine, which would not dissolve in water, to be extracted into the solvent.
Although this solvent is still used in chemistry laboratories to some degree, it has been replaced by other solvents such as 1,2-dichloroethane (ethylene dichloride) and dichloromethane (methylene chloride).
These hypochlorite scavengers are preferred because they do not contain chlorine and thus do not contribute to chlorinated hydrocarbon pollution when disposed of by incineration.
The elimination half-life for CCl4 was estimated at seven days though its concentration in the blood plasma fell below the detectable limit after taking a single deep breath from a bag of air containing less than 0.2 ppm carbon tetrachloride for a person with normal liver function, which is typically at 15 minutes post-exposure.
The danger of working with carbon tetrachloride is that it forms explosive organic peroxides upon exposure to light or elevated temperatures.
Carbon tetrachloride should be stored in an opaque container and away from heat or flame.
Also, because it has an unpleasant odor, carbon tetrachloride should not be used without thorough ventilation, such as in fume hoods.
What Does It Mean When a Substance Is Polar or Non-Polar?
A polar molecule is one in which the positive and negative poles are not symmetrical. In other words, the molecule contains regions that are distinctly positive and negative. Water is an example of a polar molecule.
A non-polar molecule, on the other hand, has symmetrical poles, that is, the positive and negative regions of the molecule are evenly balanced.
Hydrocarbons (molecules composed of only hydrogen and carbon) are typically non-polar molecules. Water and hydrocarbons don’t mix, they’re said to be immiscible.
Water, on the other hand, mixes with ethanol (a compound in alcoholic drinks) because ethanol molecules are polar.
The third category of solute (something dissolved in a liquid) is called a nonelectrolyte.
“Nonelec” in nonelectrolyte means no electricity.
A nonelectrolyte is a molecule that does not ionize when dissolved in liquid.
An electrolyte is a molecule that ionizes when dissolved in liquid, effectively dissociating into two parts: one which takes an electron and another which gives up an electron.
Molecular compounds containing atoms capable of taking or giving up electrons are termed ions by chemists.
Why is Carbon Tetrachloride Polar?
Carbon tetrachloride is polar because it has a high electronegativity. This means that it attracts electrons to itself more than other atoms.
When two molecules interact, the one with the higher electronegativity will pull the electrons away from the other.
This creates a separation of charge, and the molecule becomes polar.
When an electrically neutral molecule has one atom with very high electronegativity, this will pull the electrons away from another part of the molecule.
This is called partial ionic character.
There is still some covalent bond to the polar bond.
So it’s not fully ionic or fully covalent, but partially both.
Carbon tetrachloride’s polarity makes it soluble in many other substances because its molecules can interact with those of other solvents and dissolve into them.
Carbon tetrachloride is less dense than water due to its strong polarity which forces increased energy on its molecules when they are trapped between water molecules in liquid form.
When carbon tetrachloride is in gaseous form, it has a very low boiling point because its molecules are easily separated by heat.
Carbon tetrachloride’s polarity also gives it an extremely high solubility for organic compounds and makes it a great solvent to use with non-polar substances.
Carbon tetrachloride is a polar molecule because it has two different types of atoms; carbon, and chlorine.
Polar molecules are electrically charged at one end with an unequal distribution of electrons on their opposite ends.
Carbon tetrachloride is composed of four chlorines and eight carbons.
The difference in electron charge between each atom creates polarity within the molecule.
This also means that when you look down from above, it will be negatively charged (left) and positively charged (right).
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