Chemistry Data
Chemistry data on chlorine dioxide , chlorine, and oxygen:
By Andreas Kalcker
Chlorine dioxide
The controversy surrounding chlorine dioxide often stems from misconceptions about its properties and uses, leading to misguided assumptions. Many individuals mistakenly equate chlorine dioxide gas with its aqueous solution, overlooking the significant differences in their chemical behavior and safety profiles.
While ClO₂ gas is a potent oxidizer with potential health risks, the aqueous solution is used in controlled environments for disinfection and water treatment at safe concentrations. This misunderstanding has fueled unfounded claims about its efficacy and safety, particularly in medical treatments, where it is misrepresented as a miracle cure. Such assumptions not only mislead the public but also undermine scientific evidence regarding its appropriate applications, highlighting the importance of clear communication and education about chlorine dioxide and its proper uses.
The mixture of sodium chlorite (NaClO₂) with an acid also known as MMS differs significantly from simply dissolving chlorine dioxide (ClO₂) gas in water. When NaClO₂ is combined with an acid, it undergoes a chemical reaction that generates ClO₂ gas, alongside other byproducts. This reaction involves the conversion of chlorite ions (ClO₂⁻) into chlorine dioxide through the protonation of the chlorite ion in the acidic environment.
In contrast, dissolving ClO₂ gas in water does not involve any conversion or secondary reactions; it remains as ClO₂ molecules in solution.
Like ozone and chlorine, chlorine dioxide is an oxidizing biocide and not a metabolic toxin , moreover, the concentration and behavior of the resulting ClO₂ will differ between the two scenarios. In the case of mixing sodium chlorite with an acid, the reaction can produce varying amounts of ClO₂ depending on the concentration of the acid and sodium chlorite, leading to potential variations in efficacy and safety. This distinction is crucial because the chemical environment and concentration can influence the effectiveness of ClO₂ as a disinfectant or its safety profile when ingested. Understanding these differences is key to recognizing the appropriate contexts for using each form.
| Property | Chlorine Dioxide Gas (ClO₂) | Chlorine Dioxide Aqueous Solution |
|---|---|---|
| Chemical Name | Chlorine Dioxide | Chlorine Dioxide |
| Chemical Formula | ClO₂ | ClO₂ |
| Molar Mass (g/mol) | 67.45 | 67.45 |
| Appearance | Yellowish-green gas | Yellowish liquid |
| State | Gas | Aqueous solution |
| Solubility in Water | Low solubility (generally not applicable) | Highly soluble |
| Concentration in Aqueous Solution | Not applicable | Varies (typically 0.1% to 5%) |
| pH | Not applicable | Typically 4.5 to 7.5 |
| Oxidation State of Chlorine | +4 | +4 |
| Boiling Point (ºC) | 11.8 | Decomposes in solution |
| Melting Point (ºC) | -59.5 | Not applicable |
| Density (g/ml) | 1.64 | Approximately 1.0 (depends on concentration) |
| Reactivity | Strong oxidizing agent | Strong oxidizing agent |
| Common Uses | Disinfectant in gaseous form | Water treatment, disinfectant, bleaching, and medicinal applications |
| Toxicity | Toxic at high concentrations; irritant | Established by EPA as 292 mg/kg when present as gas in water |
| Regulatory Status | Regulated as a hazardous material | Regulated as a disinfectant and sanitizer; studied for medical use |
| Stability | Unstable; decomposes | Decomposes over time; requires proper storage |
| Decomposition Products | Chlorine and other byproducts | small amounts of Chlorine, chlorite, and other byproducts |
| Oxidizing Properties | Effective oxidant against lower ORP | Effective oxidant against lower ORP |
| Reducing Properties | Not significant | Acts as a reductant against OH* and superoxide radicals |
| Medical Applications | Not typically used in gas form | Used successfully in medicine with proven studies for treating infections, wounds, and water purification |
| Mechanism of Action | Disrupts cellular function through oxidation | Increases oxygen levels and electromolecular charge (ORP) in the body; disrupts microbial cell membranes and virus through oxidation |
| Stability in Storage | Requires careful handling due to instability | Should be stored in a cool, dark place to maintain effectiveness |
| Interactions with Other Chemicals | Can cause explosions under pressure (>10%) or strong UV light; reacts vigorously with organic materials and ammonia; can generate heat and toxic gases | Generally stable; should be handled with care; does not pose the same explosive risks as gas; can react with certain organic compounds but is less hazardous than the gas form |
| Environmental Impact | Can produce harmful byproducts if not managed | Biodegradable under certain conditions; can affect aquatic life at high concentrations |
Table with information about oxygen:
Oxygen is a highly reactive element and a strong oxidant, playing a crucial role in various chemical processes. It is known to be harmful to many pathogens, as its reactive nature can damage their cellular structures and lead to their destruction. For instance, oxygen can produce reactive oxygen species (ROS) that are toxic to bacteria and viruses.
Additionally, in its liquid form, oxygen exhibits bleaching properties. Interestingly, oxygen possesses magnetic properties, specifically being paramagnetic; it has two unpaired electrons that allow it to be attracted to magnetic fields. These magnetic properties are essential for the uptake of oxygen by red blood cells (RBCs) in the lung alveoli, as they facilitate the binding of oxygen to hemoglobin. This is complemented by osmotic pressure, which also plays a role in the transport of gases.
Despite its reactivity and potential hazards, oxygen is essential for human life, as it is critical for cellular respiration. Human cells utilize oxygen to convert glucose into ATP (adenosine triphosphate), the energy currency of the cell, through aerobic respiration. This process not only supports energy production but also plays a vital role in metabolic functions necessary for sustaining life.
| Property | Value |
|---|---|
| Name | Oxygen |
| Atomic Number | 8 |
| Group | 16 (Chalcogens) |
| Period | 2 |
| Block | p-block |
| Valence | 2 |
| Oxidation State | -2 |
| Electronegativity | 3.5 |
| Covalent Radius (Å) | 0.73 |
| Ionic Radius (Å) | 1.40 |
| Atomic Radius (Å) | - |
| Electronic Configuration | 1s² 2s² 2p⁴ |
| First Ionization Potential (eV) | 13.70 |
| Atomic Mass (g/mol) | 15.9994 |
| Density (kg/m³) | 1.429 |
| Boiling Point (ºC) | -183 |
| Melting Point (ºC) | -218.8 |
| Discoverer | Joseph Priestley 1774 |
| Color | Colorless gas; blue when liquid |
| Taste | Tasteless |
| Odor | Odorless |
| Natural Occurrence | About 21% in the atmosphere |
| Isotopes | , , |
| Reactivity | Highly reactive |
| Uses | Essential for respiration, water purification, rocket fuel oxidizer |
| Molecular Form | Diatomic |
| Allotropes | Ozone |
Table with the information about chlorine:
Chlorine and chlorine dioxide are distinct chemical entities, each with unique properties and behaviors in an aqueous solution. Chlorine (Cl₂) is a diatomic molecule that acts as a strong oxidizing agent, primarily used for disinfection and water treatment. When dissolved in water, it forms hydrochloric acid (HCl) and hypochlorous acid (HClO), which contribute to its disinfecting properties. However, chlorine is highly toxic, and its presence in drinking water can pose serious health risks, including respiratory issues and irritation to the eyes and skin.
On the other hand, chlorine dioxide (ClO₂) is a compound made up of one chlorine atom and two oxygen atoms, known for its effectiveness as a bleaching agent and disinfectant. In an aqueous environment, chlorine dioxide remains largely undissociated and does not convert into chlorine or any chlorine-containing species. The mechanisms by which these two substances operate are different; while chlorine primarily targets organic contaminants through oxidation, chlorine dioxide is more selective, efficiently targeting specific pathogens without forming chlorinated by-products. Therefore, despite their similar names and overlapping applications in water treatment, chlorine and chlorine dioxide operate independently and do not interact to form one another in an aqueous solution.
| Property | Value |
|---|---|
| Name | Chlorine |
| Atomic Number | 17 |
| Valence | +1, -1, 3, 5, 7 |
| Oxidation State | -1 |
| Electronegativity | 3.0 |
| Covalent Radius (Å) | 0.99 |
| Ionic Radius (Å) | 1.81 |
| Atomic Radius (Å) | 0.99 |
| Electron Configuration | [Ne] 3s² 3p⁵ |
| First Ionization Potential (eV) | 13.01 |
| Atomic Mass (g/mol) | 35.453 |
| Density (g/ml) | 1.56 |
| Boiling Point (ºC) | -34.7 |
| Melting Point (ºC) | -101.0 |
| Discoverer | Carl Wilhelm Scheele (1774) |
| Color | Greenish-yellow gas |
| State at Room Temperature | Gas |
| Isotopes | Cl-35, Cl-37 |
| Solubility in Water | Soluble |
| Molecular Weight (g/mol) | 70.906 |
| Common Compounds | NaCl, HCl, ClO₂ |
| Uses | Disinfectants, bleach, water treatment |
