Is H2S Polar or Nonpolar?

Answer: H2S is a polar molecule due to the presence of lone pair electrons at the top of the molecule causing a region of partial negative charge due to electron-electron repulsion. 

H2S has a very similar structure as H2O (see the lewis dot structure for H2O and the polar/nonpolar explanation at the linked addresses). However, due to the larger size of the sulfur atom compared to oxygen, the bond angle (i.e. the smaller angle between the two hydrogen atoms) is only 92˚ compared to 107.5˚ for H2O. Sulfur contains many more electrons which ultimately due to electron-electron repulsion require a lot more space. Nevertheless the decreased electronegativity of sulfur when compared to hydrogen (2.58 vs. 2.20, respectively) means that the molecule is much less polar overall when compared to H2O. This means that it has a much lower melting and boiling point at -82˚C and -60˚C, respectively. Like SO2 the presence of sulfur means that this molecule has a pungent odor in gaseous form although it is colorless. 

H2S Ball and Stick Diagram. Created with MolView.

How is H2S utilized in the real world?

Hydrogen sulfide appears in many different ways within the natural world. For starters it is an important constituent of the sulfur cycle. Bacteria oftentimes convert the sulfur from organic elements to inorganic molecules such as H2S. The main use of hydrogen sulfide is as a storage compound which can be converted to pure sulfur during reactions to form all kinds of sulfur-containing compounds. Hydrogen sulfide may have also caused a mass extinction due to its buildup within the atmosphere. Based on this fact it is not difficult to imagine the toxicity of hydrogen sulfide towards life forms such as human beings. It negatively impacts proper nervous system functioning primarily although it will affect other body systems as well. Nevertheless there are certain organisms adapted to live in high-H2S conditions due to those environments existing in deep underwater volcanic sea vents.  

The Lewis Dot Structure for Acetic Acid (CH3COOH)

Created by MakeTheBrainHappy.

Above is the Lewis Dot Structure for Acetic Acid (CH3COOH). You could alternatively also draw the structure by including two dots for every bond. As you can see every single element has a filled valence shell with the two oxygen's each containing two lone pairs of electrons, the only instance of this phenomena within the Lewis Structure. In a sense this is a modified structure of methane (CH4) with the replacement of one hydrogen with the replacement of a carboxylic group (-COOH). As we will see the properties we observe within the Lewis structure have a significant impact on the properties of acetic acid.

The Greek Philosopher Theophrastus. Source

What is the history of acetic acid?

Due to the importance of different alcohols such as beer and wine in early civilizations, vinegar became one of the earliest chemical substances that was familiar to ancient peoples. Vinegar is formed by natural fermentation processes and contains approximately 5% acetic acid. One of the earliest mentions of acetic acid was by the Greek Philosopher Theophrastus who explained how to form different pigments, including those for white and green colors, with vinegar as an important constituent ingredient. 

Is Acetic Acid (CH3COOH) Polar or Nonpolar?

Acetic Acid (CH3COOH) is a polar molecule due to the presence of the functional group COOH, a carboxylic acid. It is also an acid in solution, releasing a small number of protons into solution which form H3O+. Due to its polar qualities it is found as a liquid at standard temperature and pressure in relation to its rather light molar mass. It has a melting point is between 16˚C to 17˚C while the boiling point is between 118˚C and 119˚C. These are again elevated due to the polarity of acetic acid. 

How is Acetic Acid (CH3COOH) utilized in the real world?

Acetic acid is useful due to its properties as a polar solvent and building block for other molecules, containing both a methyl (CH3) and COOH functional group. Nearly one third of produced acetic acid is utilized in order to produce "Elmer's glue" material. Inks, paints and coatings are also created via a reaction involving acetic acid. It is frequently utilized as a polar solvent in lab research settings and thereby has been involved in certain medical practices. As mentioned above acetic acid is also present in vinegar which has a variety of household uses; however, the acetic acid is diluted in water to a greater degree than in a research lab.  

The Lewis Dot Structure for KCl

Created by MakeTheBrainHappy.

Please find above the Lewis Dot Structure for KCl (Potassium Chloride). As per usual you could replace the one bond with two electrons. In the case for KCl the electronegativity difference between potassium and chloride is so strong (.82 vs. 3.16, respectively) that the bond is considered ionic. The electrons aren't really considered "shared"; rather, the valence electrons are nearly completely coopted by the chloride. This property as illustrated by the Lewis Dot Structure gives KCl many of its properties as will be explored in the following paragraphs.

KCl Dissolving in Water. Source

How does KCl (potassium chloride) act as a solute?

As a result of its ionic character as shown in the Lewis Dot Structure it has a great partial positive and partial negative charge on either end. Therefore it dissolves very well in polar solvents such as water (shown above). Water molecules essentially surround the different individual ions and thereby disassociate the salt into solution. However since you need many water molecules per ion there can be a point where you saturate the solution. This means that no more salt can be disassociated unless you add more of the polar solvent.

KCl Molecule. Created with MolView.

Is KCl (potassium chloride) polar or nonpolar?

As you may have guessed from the above paragraph, KCl is a polar molecule due to the great electronegativity difference discussed before. This incredibly large difference means that the compound is a solid at standard pressure and temperature with a melting point of 770˚C and a boiling point of 1420˚C. The act of disassociation as mentioned above is not equivalent to melting the pure compound into a liquid as we are discussing here. These properties are also presupposed in the Lewis Dot Structure for KCl.

KCl Salt. Source

How is KCl (potassium chloride) utilized in the real world?

There are a wide variety of uses for potassium chloride. There are different fertilizers which are composed of KCl for usage in agriculture. Due to the necessity of potassium in biological systems the salt form shown above is often consumed by those who are potassium-deficient. In regular food it can be utilized as a table salt (NaCl) substitute in order to lower the actual Na+ salt content in someones diet. Lastly it is found in many different niche industrial uses as a "ice" salt or in the creation of potassium metal for example. In conclusion, the different properties that allow for these utilizations are exemplified by the Lewis Dot Structure for KCl.

The Lewis Dot Structure for CS2

CS2 Lewis Structure. Created by MakeTheBrainHappy

This is the Lewis Dot Structure for Carbon Disulfide (CS2). As we've discussed before you could replace each bond with two electrons which would represent well how through the sharing of electrons each atom achieves a full octet. The combination of four electrons for the bonds and four electrons in lone pairs equals eight for sulfur while bonds supply eight electrons for the central carbon atom. This is a common feature for carbon as it is unlikely for this element in particular to have lone pair electrons.

The lewis dot structure for CS2 also predicts many of the properties of the molecule. Due to the presence of large sulfide atoms over for comparison oxygen atoms in CO2 the molecule has a greater capacity for temporary london dispersion forces. As a result there can be more induced dipoles which increases the solubility of CS2. The compound is slightly soluble within water and much more soluble in less polar compounds such as alcohol or even nonpolar compounds like benzene.

CS2 Liquid State. Source

How is CS2 utilized in the real world?

Due to the stronger induced dipoles CS2 also has a greater melting and boiling point. This means that the compound is a liquid at standard temperature and pressure. This concept is discussed further in our article on the polarity of CS2 which you can learn more about in the next section. There are only a limited number of uses for CS2 due to its pretty toxic properties. One of these uses is as a solvent for other nonpolar compounds. These include many elements like phosphorus and sulfur and also larger compounds like fats, resins and rubber. There also other uses for different chemical reactions involved in metallurgy and rubber production. One of the most popular reactions involving CS2 produces carbon tetrachloride (CCl4).

Is CS2 polar or nonpolar?

If you are interested in learning more about this subject, feel free to read this article on whether CS2 is polar or nonpolar. The article will also discuss some of the ways in which CS2 differs from CO2. In addition it will also go into the underlying reasons behind the determination of CS2s polarity.

Volcanic eruption. Source

How can CS2 be formed naturally?

CS2 (carbon disulfide) can be formed naturally by volcanic eruptions or in marshes. The way this reaction occurs is actually very compatible with how you can see the molecule within the Lewis Dot Structure. Elemental carbon and sulfide combine at very high temperatures to form CS2. However, it should be noted that there is only a very small amount of the compound formed in this process. 

Is SO2 Polar or Nonpolar?

Answer: SO2 is a polar molecule because the lone pair of electrons on the central sulfur atom cause electron-electron repulsion that forces a bent structure leading to an unequal distribution of charge throughout the molecule. 

Due to the molecules relatively strong dipole, the compound a melting point of -72˚C and a boiling point of -10˚C. This means that SO2 is a gas at standard temperature and pressure. The gas is found at low concentrations in earths atmosphere at less than 1 ppm. It features more prominently on the atmospheres of other plants. For example, Venus has an atmospheric concentration of 150 ppm SO2. It can be produced from constituent elements or sulfites. The molecule is said to have a pungent smell- similar to a just-struck match. 

SO2 Ball and Stick Diagram (one of two resonance structures). Made with Avagadro.

How is SO2 utilized in the real world?

Sulfur dioxide is most commonly utilized as an intermediate in the production of sulfuric acid. It can be used as a preservative for dried fruits and it has played an important role ini wine-making for millennia. On a chemical note it serves as an excellent reducing agent in many reactions and biochemical systems. At lower temperatures it is also utilized as a solvent. It is a major air pollutant.

Is HCl Polar or Nonpolar?

Answer: HCl is a polar molecule due to the large electronegativity difference between Chlorine (3.16) and hydrogen (2.20). This causes a region of partial positive charge on the hydrogen atom and a region of partial negative charge on the chlorine halide. 

Typically the formula HCl can refer to one of two "concepts": the compound hydrogen chloride and hydrochloric acid, the aqueous form of hydrogen chloride. The compound has a melting point of -114˚C and a boiling point of -85˚C. This means that it is a gas at standard temperature and pressure. As mentioned the compound is soluble in water but it is also soluble in slightly less polar molecules such as ethanol and acetone. It is described as having a "pungent" odor. Hydrogen chloride has an in fact quite storied history being originally discovered by alchemists in the middle ages. Today it is recommended that HCl be handled with extreme caution as HCl forms a corrosive acid when inhaled or when in contact with any part of your skin.

HCl Ball and Stick Diagram. Created with MolView.

How is HCl utilized in the real world?

Basically all of the prominent uses of HCl are for hydrochloric acid. This includes removing impurities from steel, as a reagent in the production of organic products utilized in pharmaceutical manufacturing, pH control and oil processing. The acid is also present within organism's digestive tract to support the process of degrading eaten foodstuffs.

Is CF4 Polar or Nonpolar?

Answer: CF4 is a nonpolar molecule due to the symmetrical tetrahedral structure which cancels out the different electron pulls by the extremely electronegative fluorine atoms. 

As a result of its nonpolar character carbon tetrafluoride has a melting point of -184˚C and a boiling point of -128˚C. This means that the compound is a gas at standard temperature and pressure. Due to the large electronegativity difference between fluorine (3.98) and carbon (2.55), the molecule is noted for an incredibly high bond strength. This is due to the partially positive carbon giving the molecular structure some ionic character. In fact carbon-fluoride bonds are noted to be the strongest bonds in organic chemistry. Tetrafluoromethane is naturally produced when you burn any carbon compound in an atmosphere of fluorine. In industrial applications the molecule is produced by combining CCl2F2 and HF.

CF4 Ball and Stick Diagram. Created with MolView.

How is CF4 utilized in the real world?

Due to the strength of the C-F bonds the compound is very stable and will only react with extreme elements like pure alkali metals. In industry the molecule is sometimes used as a refrigerant. Therefore CF4 is sometimes called R-14. As with many carbofluorides tetrafluoromethane can be used as a plasma etchant in this case specifically on silicon derivatives. Due to the molecules higher density it can also be utilized in neutron detectors. However these same properties make the structure one of the most persistent and potent greenhouse gases. The high density also means that CF4 will crowd our regular air, leading a risk of asphyxiation in poorly ventilated spaces.

Is CH2Cl2 Polar or Nonpolar?

Answer: CH2Cl2 is a polar molecule due to the unequal distribution of charge caused by the pull of electrons from the hydrogen atoms to the chlorine atoms due to hydrogen (2.20) have a lower electronegativity than chlorine (3.16). 

As a result of strong intermolecular forces caused by its polar properties, Dichloromethane has a melting point of -96.7˚C and a boiling point of 39.6˚C. This makes the compound a liquid at standard temperature and pressure. Although the liquid form is volatile, the compound is widely utilized as a solvent. Even though it does not form a solution with water, it can dissolve a wide variety of organic compounds which is why it is utilized as a solvent. CH2Cl2 is naturally produced in wetlands by macroalgae and in volcanic eruptions; however, the majority of the compound on earth is produced by humans in industrial processes. The structure is said to have a "sweet" aroma.

CH2Cl2 Ball and Stick Diagram. Created with MolView.

How is CH2Cl2 utilized in the real world?

In addition to being used as a solvent CH2Cl2 has been applied in the food industry to decaffeinate coffees and teas. The substance due to its low boiling point can extract mechanical energy from small temperature differences. Furthermore the compound can be used to weld certain plastics together. Although it is considered the least toxic of the simple chlorohydrocarbons, dichloromethane still poses serious health risks to overexposed individuals. Products with "DCM" are generally forced to label this on their packaging. It is believed that CH2Cl2 does not impact the ozone layer because it degenerates before reaching the stratosphere.

Is CH2O Polar or Nonpolar?

Answer: CH2O is a polar molecule due to the presence of a very electronegative oxygen (3.44) on one side of the molecule inducing a partial negative charge with the hydrogens carrying a partial positive charge due to hydrogen's lower electronegativity value (2.20).

Formaldehyde has a melting point of -92˚C and a boiling point of -19˚C as a result of its polar character. This means that the compound is a gas at standard temperature and pressure. It is also very soluble within other polar compounds such as water. Formaldehyde is mostly produced by processes in the upper atmosphere which account for 90% of its natural product. Processes such as forest fires and automobile exhaust systems also contribute CH2O to the environment. This molecule has also been found in interstellar space. There are many reactions involving formaldehyde within organic chemistry.

CH2O Ball and Stick Diagram. Created with MolView.

How is CH2O utilized in the real world?

The structure is a quite common precursor to many more complex molecules, including resins and finishes. There are a wide variety of niche uses as well including as a disinfectant and in photography. The compound is considered a human carcinogen at higher concentrations although your body naturally produces and requires a certain amount of formaldehyde. Certain countries have in fact banned manufacturing and importation of CH2O. There were also incidents in the 2000s where large quantities of foodstuff were contaminated in countries like Indonesia and Vietnam where the chemical was added to extent the shelf life of products.

Is CH3Cl Polar or Nonpolar?

Answer: CH3Cl is a polar molecule due to the partial negative dipole induced around the chlorine atom due to chlorine's high electronegativity (3.16) and the partial positive charges on each of the hydrogen atoms (electronegativity for hydrogen: 2.20). 

As a result chloromethane has a melting point of -97.4˚C and a boiling point of -23.8˚C. This means that the compound is a gas at standard temperature and pressure. This gas is often produced by the sugar cane industry during the burning of waste. When released it is said to have a lifespan of one to three years before decaying in the atmosphere. It also naturally occurs in marine phytoplankton and other kinds of bacteria which have an enzyme that synthesizes CH3Cl. It also also been detected as a trace gas in the interstellar space. It is described as having a "faint-sweet" odor.

CH3Cl Ball and Stick Diagram. Created with MolView.

How is CH3Cl utilized in the real world?

It was originally produced in 1835 by boiling a mixture of methanol, sulfuric acid and sodium chloride. This technique is still utilized today as chloromethane is widely utilized in reactions that produce compounds containing carbon, chlorine and silicon. It used to be within refrigerants. As a result the compound is also called Refrigerant-40. However this has been discontinued since the compound is labelled as a carcinogen with the same effects to the central nervous system as alcohol.

Is HCN Polar or Nonpolar?

Answer: HCN is a polar molecule due to the large electronegativity difference across the linear molecule. The electronegativity difference between nitrogen (3.04) and hydrogen (2.20) is large enough to qualify this molecule as polar. 

As a result the molecule has a relatively high melting point of -13.3˚C and boiling point of 26˚C. This means that the compound is a liquid at standard temperature and pressure. It is able to form solutions with other polar substances such as water and ethanol. It is however extremely poisonous and flammable due to the instability of the triple bond (there are many different electrons packed into this configuration). As a result on the historical uses of hydrogen cyanide was as a chemical weapon in wartime. Today it is mainly utilized in gold and silver mining in order to purify those substances. Furthermore, it is utilized in the process of electroplating these same ions on other electrodes.

If you are interested in learning more about the lewis dot structure of HCN, feel free to check out this article.

HCN Ball and Stick Diagram. Created with MolView.

Where does hydrogen cyanide occur naturally?

HCN occurs in many different places in minute concentrations which ensures relatively low toxicity. For example there is a small quantity within the pits of dried fruits such as apples, apricots and cherries. Phagocytes within the human body also naturally produce HCN when they are destroying a certain particulate. It also has been detected in Tobacco smoke. However some of the most interesting theories concern the natural occurence of HCN in space. It naturally forms in interstellar clouds as a compound of pure elements. It has also been detected in the moons of other planets such as the moon Titan.

Is N2 Polar or Nonpolar?

Answer: N2 is a nonpolar molecule because there is no electronegativity difference across the linear structure because the molecules are identical. This means that there are no permanent dipoles within the structure. 

Nitrogen is one of the most important elements on earth since it has a wide variety of applications. Due to the nonpolar properties and relatively few electrons, the compound has a quite low melting point of -210˚C and a boiling point of -196˚C. This means that the compound is a gas at standard temperature and pressure. It makes up about 78% of earth's atmosphere. Lavoisier, who is most noted for discovering oxygen (O2),  gave the compound the name azote which is what the compound is called in many languages in the present day.

N2 Ball and Stick Diagram. Created with MolView.

How is nitrogen (N2) utilized in the real world?

Although nitrogen is approx. 78% of the atmosphere, only 3% of the compounds in the human body involve nitrogen of some kind, especially amine groups. However this is enough for an entire nitrogen cycle to exist which filters these nitrogen-containing molecules through an entire cycle between earth and atmosphere. It is utilized in fertilizers for agricultural applications. Liquid nitrogen is commonly utilized as a refrigerant to keep items in especially freezing conditions. Nitrogen-containing compounds even make up the material that we know as Kevlar which is an incredibly strong and durable protective shield. There are some many ways that N2 is utilized however these applications often rely on nitrogen-containing compounds rather than pure nitrogen. Therefore this listing will end; however, we recommend checking out some of our other articles concerning carbon-compounds within the "polarity" series. Click on the "polarity" sidebar tag in order to see the whole selection!

The Lewis Dot Structure for NO2+

Created by MakeTheBrainHappy

Please find the Lewis Dot Structure for NO2+ (also known as nitronium ion) shown above. As with all other Lewis Dot Structures the bonds within the structure can be replaced by two dots. Both of the oxygen's on the ends of NO2+ contain two lone pairs of electrons and are chemically neutral. The +1 positive charge within NO2+ is present on the central nitrogen atom which is the least electronegative species in the molecule (3.04 vs. oxygen's 3.44).

The presence of this positive charge induces a quite strong attraction for the molecule as a whole to balance this out either with a negatively charged cation or with an extra electron. In fact the NO2 neutral species with an extra electron tacked onto the nitrogen is quite unique in its stability when compared to similar molecules with electrons lacking a pair. If you are interested in learning more about the reaction for forming NO2+, then I would highly recommend this recently published video lecturing on aromatic ring substitution. 

Different kinds of nitrated benzene rings. Source

This principle brings us to the second stable conformation of NO2+. As the Lewis Dot Structure reveals, the compound would not exist in a stable form and requires negative charge to balance it out. This can often be supplied by a negative cation such as PF6-, forming a stable nitronium salt. These salts are most often utilized in order to add NO2 species to other molecules such as the benzene rings shown in the diagram above. Researchers in that lab attempted to add NO2 species to benzene rings under different acidic conditions to understand which would be most effective at producing different results.

Is NO2+ polar or nonpolar?

If you are interested in learning more about this subject, your in luck! We've written an entire article regarding this subject: https://www.makethebrainhappy.com/2020/04/is-no2-polar-or-nonpolar.html. The interesting properties result from the complex interaction between its structure as determined by polarity and its status as a cation. This again goes back to the structure as elucidated by the Lewis Dot Structure for NO2+.  

The Lewis Dot Structure for CH4

Created by MakeTheBrainHappy.

The Lewis Dot Structure for CH4 is shown above. These kinds of structures can also be shown by representing each of the bonds with two dots. Each atom in the bond has a full valence, with carbon having access to eight electrons and each hydrogen having access to two (this is why hydrogen only needs two). The covalent bonds between the C and the H are similar to the ones formed between two Hs because the relatively small difference in electronegativity between carbon and hydrogen.

Methane is a tetrahedron structure in 3D space. Source

This Lewis Dot Structure also explains some of the fundamental properties of this particle. Since there are no lone pairs on the central atom (or any atom for that matter) there are few dipoles created and the minimal electronegativity difference means that these bonds can essentially be treated as nonpolar covalent bonds. This means that all attraction forces inside the molecule rely on weak London Dispersion Forces which only strengthen in far larger atoms. In fact the molar mass of Methane is so minuscule that it is sometimes mentioned as a possible lifting gas because its density is less than that of air. It boils at -161˚C due to the weak intermolecular forces present and normally exists as a colorless, odorless gas at STP (Standard Temperatures and Pressures).

Methane in a Solid State. Source

Does Methane exist in other states?

Yes- it is theoretically possible to find methane in other states of matter (liquids, solids). But it is extremely rare. Solid Methane is found in hydrates which have trapped methane in a more solid state. Scientists have also theorized that the lakes of Titan, one of the moons of Saturn, are composed of Liquid Methane. Due to the low boiling and melting points, it is rare to find these other states present.

Is CH4 an acid or a base?

Methane does not really have classic characteristics of either an acid or a base but it has been classified as a very weak acid. It will not release a hydrogen in solution but it has been shown to release a hydrogen in low-pressure gas mixtures such as the upper atmosphere. However, it should be noted that all of the different species produced in these reactions are extremely unstable.

Is it soluble in water?

No- Methane is not soluble in water because it does not have polar/strong intermolecular forces needed to break the hydrogen-bonds found in water. Therefore is is classified as insoluble. However it is soluble in less polar solutions such as ethanol and acetone to a far greater degree.

Methane from a gas burner stove. Source

How do Methane Emissions affect the Earth?

This article should have more information about to answer this question. A common statistic is that methane is a greenhouse gas 84 times more potent than CO2.

Methane Cycle. Source

What are the natural sources of CH4 (methane)?

There are a wide variety of sources that contribute to the cycling of methane within the earth. In terms of natural processes there are different microbes that will either release or take in methane to utilize for cellular metabolism. Most organisms as shown in the diagram are contributing methane to the environment. The imbalance within this cycle is caused by additional methane created through the burning of biomass and fossil fuels. Ultimately these agents react within the atmosphere to form power hydroxide ion oxidizers that are able to take a hydrogen from methane (CH4) - an incredibly difficult task as discussed before in this article in the section about methane as an acid.

Is CH4 polar or nonpolar?

We've written an entire article on whether CH4 is polar or nonpolar! Feel free to check it out at this address. As with all questions of polarity, the article examines the statement in terms of the geometric configuration and then tries to see how the varying electronegativities of the different elements impact the ultimate dipole moment. The existence of many elements with extreme electronegativities within one certain molecule can also have an impact!

Methane Cycle on Mars. Source

How else can be envision the methane cycle?

Scientists have postulated that the methane cycle is also taking place currently on Mars! Although it features different players due to the variable environment and different atmospheric composition, the same principle of sinks and releases are the same. Oftentimes it is postulated that methane is broken down into carbon dioxide and other alcohols instead of remaining as a free species in the atmosphere. For sinks it is most likely held as rock within the soil with the possibility of existing microbes either consuming and releasing methane into the atmosphere!

Sources:
https://pubchem.ncbi.nlm.nih.gov/compound/methane#section=Taste

Is SO3 Polar or Nonpolar?

Answer: SO3(2-) is a polar molecule due to the lone pair electrons at the "top" of the structure causing electron-electron repulsion and a region of partial negative charge. The resulting bent structure leads to an unequal distribution of charge rotating between the different oxygen molecules depending on which is double-bonded to sulfur and which contain single-bonds at any given moment.  

In this article we will be discussing Sulfites that contain a 2- charge as opposed to Sulfur Trioxide which relies on an expanded octet in order to complete its configuration. The latter has no charge either formal or dipole moment since it is a nonpolar molecule with a trigonal planar configuration (i.e. 120˚ between the outer molecules). The former is described by the description right above. SO3(2-) has three resonance structures with one being shown in the diagram below. The other structures move the double bond to another part of the atom with all three positions sharing this extra bond for 1/3 of the time (so each oxygen atoms theoretically has 4/3 of a bond to the central sulfur atom). Although theoretically an acid exists by combining hydrogen atoms, this has only ever been observed in the gas phase of the molecule.

SO3 Ball and Stick Diagram. Created with Avagadro.

How is SO3(2-) utilized in the real world?

Sulfites are oftentimes utilized as food additives. They occur naturally in wines, although additional sulfites may be added in order to arrest fermentation and preserve the wine for a long period of time. They may also be utilized as a preservative for other long-lasting consumables such as dried fruit. SO3(2-) oftentimes does not appear in its pure form; rather, it is added ionically-bonded to a salt such as sodium, potassium or calcium. It has been noted that there are specific allergic effects and a higher risk for those with asthma or other respiratory conditions. It is generally regulated that sulfite content be labelled on the packaging of food items. 

Is BCl3 Polar or Nonpolar?

Answer: BCl3 is a nonpolar molecule because the chlorine halides are spaced symmetrically around the central boron atom. This cancels out all of the different polar covalent bond pulls (i.e. between each of the boron-chlorine pairs as caused by the large electronegativity difference between boron (2.04) and chlorine (3.16). 

Although the species has zero dipole moment, the presence of an incomplete octet on this species as with other similar molecules such as BF3 and BH3 leads to an inherent instability within the different parts of the compound since Boron lacks a complete octet. This tension is exacerbated by the presence of the incredibly electronegative chlorines (3.16). This causes there to be an unequal distribution of charge within the molecule between the center and the outer edges. As a result BCl3 has a melting point of -107˚C and boiling point of 13˚C. This means that the compound is a gas at standard temperature and pressure. Due to this unequal distribution of general charge the compound is also soluble within slightly polar compounds such as ethanol of compounds with similar distribution of charge dispersals such as CCl4.

BCl3 Ball and Stick Diagram. Created with MolView.

How is BCl3 utilized in the real world?

Many of Boron trichloride's main uses stem from its properties as a strong acid due to the incomplete octet on the central Boron atom. Since it is quite reactive as an acid, it is often utilized to refine a wide variety of metals including Aluminum, Copper and Zinc. In many of these reactions Boron is the true agent and therefore BCl3 is really a source of Boron. The gas is also reactive enough to serve as a component of certain rocket fuels. Furthermore, it is utilized in organic reactions as a reagent in the synthesis of certain organic compounds. However it is noted that the compound should be handled with care because BCl3 will react with water and certain other alcohols to form hydrogen chloride. 

Is O2 Polar or Nonpolar?

Answer: O2 is a nonpolar molecule due to the linear structure containing two identical molecules with the same electronegativity. Therefore no permanent dipole is induced in any part of the structure. 

Oxygen has rich and storied history in its discovery although ultimately its properties of combustion led to these revelations. This was due to oxygen's high electronegativity (3.44). However O2 in its pure form is small and nonpolar. As a result it has a quite low melting point of -219˚C and boiling point of -183˚C. This means that the compound is a gas at standard temperature and pressure. The atmosphere consists of approximately 21% O2.

To learn more about the lewis dot structure for oxygen, feel free to read this post. This article also discusses the importance of the oxygen revolution and the importance of oxygen within carbon cycling. 

O2 Ball and Stick Diagram. Created with MolView.

How is O2 utilized in the real world?

There is an incredible variety in the functions of oxygen but its inarguably most important role is within biological organisms. Oxygen serves as the final electron acceptor in the electron transport chain and an important byproduct of photosynthesis. This permits the existence of complex life forms such as humans. This is why it makes sense that oxygen therapy is important in medical treatments. It also finds similar utilizations in low-pressure space suits for astronauts. Within industry the most common usage is in smelting iron ore to steel. It is also used in manufacturing of antifreeze, fabrics and plastics. More niche applications include welding, rocket fuel oxidation, and water treatment.

Is NO3 Polar or Nonpolar?

Answer: NO3- is based on its geometric structure technically a nonpolar molecule because the different oxygen atoms are dispersed in a symmetrical manner around the central nitrogen atom. However the presence of extra lone pair electrons on two of the oxygens induces regions of partial negative charge on those oxygen atoms. 

Although nitrogen trioxide (NO3) exists, it is so unstable that it has never been isolated in pure form and theoretically only serves as an intermediate in certain reactions. Therefore we will continue this discussion by focusing on the nitrate (NO3-) ion. Within this structure the nitrogen atom has a +1 charge whereas the three oxygen atoms have partial -2/3 charge. The diagram shown below exhibits one possible resonance structure: the second bond will continuously switch b/t the oxygen atoms and end up spending approximately one-third of its time with each. In this manner a partial bond is formed with each oxygen atom. Nitrates commonly form a wide variety of inorganic salts with an ionic character containing many different metal elements. Examples include KNO3 and Fe(NO3)3.

NO3 Ball and Stick Diagram. Created with Avagadro.

Where is NO3- commonly found in the real world?

There are a wide range of nitrate sources. It is found in our diets via green foods and cured meats. The salt is present within the earth in relatively high concentrations again in salt form. Indeed some bacteria have even evolved to utilize NO3- as a food source. Within industrial uses nitrates feature prominently as fertilizers in agriculture. They are deemed not toxic but there is a small risk of nitrates degrading to nitrites (NO2-) which are a possible carcinogen.

Is NO2 Polar or Nonpolar?

Answer: NO2 is polar molecule due to the presence of a lone pair of electrons whose electron-electron repulsion results in a bent structure. This unequally distributes charge within the molecule and thereby induces a permanent dipole. 

Due to the presence of only one lone pair of electrons on the central nitrogen as opposed to for example H2O with two lone pairs on the central oxygen, we find that NO2 has a larger central angle nearly 30˚ greater than H2O's "bent" structure. This combined with nitrogen dioxides electronegative oxygen atoms (3.44) on the ends decreases the dipole moment significantly. As a result NO2 has a melting point of -9.3˚C and a boiling point of 21˚C. It is soluble in less polar compounds like CCl4 and chloroform. It is said to have a "reddish-brown" color at higher temperatures.

NO2 Ball and Stick Diagram. Created with Avagadro.

How is NO2 utilized in the real world?

Nitrogen dioxide finds use in a wide variety of reactions to product for example nitric acid or nitrites. It has also found use in rocket fuels since it is a strong oxidizer having a strong affinity for electrons. However these same properties make the compound toxic to human health as the molecule will react in the respiratory system. This has been associated with an increase in asthma cases. The 2000 census indicated that half of U.S. households use gas stoves which increase threefold the risk of NO2 poisoning.

Is CHCl3 Polar or Nonpolar?

Answer: CHCl3 is a polar molecule due to the large electronegativity difference between hydrogen (2.20) and chlorine (3.16). This induces a permanent dipole across the molecule with a partial positive charge on the hydrogen atom and a partial negative charge on the chlorine atoms. 

Since the one hydrogen on the structure (2.20) is outnumbered by three very electronegative chlorines (3.16), chloroform has a quite strong dipole moment. As a result the molecule has a melting point of -64°C and a boiling point of 61°C. This means that the compound is a liquid at standard temperature and pressure. While it is not incredibly soluble in water, it has much higher solubility in less polar solvents such as alcohol. The molecule is produced naturally by many kinds of seaweed and fungi.

CHCl3 Ball and Stick Diagram. Created with MolView.

How is CHCl3 utilized in the real world?

Chloroform is utilized a solvent for a wide variety of materials including fats and rubbers. It also provides -CCl2 groups in reactions. Historically it was utilized as an anesthetic but it was abandoned in the early 1900s since many persons experienced cardiac arrest as a side effect. It has been labelled a "hazardous" material and possible carcinogen. It is recommended that one limit exposure whenever possible.