Basic Information about NO₂:

Nitrogen is a mainly diatomic nonmetal gas that is generally colourless, odourless, and tasteless. In most compounds, it is trivalent because its outer shell has five electrons. The majority of nitrogen molecules are present in the atmosphere. Nitrogen is found in the form of nitrates and nitrites in water and soil. All of these elements are part of the nitrogen cycle, and they are all interconnected. 

Atomic number of nitrogen: 

The atomic number is the number of protons in the nucleus of each atom of an element (represented by the symbol Z). An atom’s atomic number can be used to classify it as a certain element. 

The number of protons equals the number of electrons in an atom.

As a result, the number of electrons in nitrogen equals 7.

As a result, nitrogen’s atomic number is 7. 

Mass number of nitrogen: 

The mass number, also known as the atomic mass number or nucleon number, is the total amount of protons and neutrons in an atomic nucleus. It’s about the same as the atom’s atomic mass expressed in atomic mass units. 

Between carbon and oxygen, nitrogen is the seventh element in the periodic table. Nitrogen has an atomic mass of 14.01 amu (14.01 g/mol). 

Molar mass of nitrogen: 

Nitrogen, with the symbol N, atomic number 7, and atomic mass 14.00674μ, is a chemical element. 

The mass of the N₂ molecule in nitrogen is 

N₂ = 14.01 + 14.01

N₂ = 28.02

As a result, a nitrogen molecule has a molecular or molar mass of 28μ.

Oxides of nitrogen: 

Nitrogen combines with oxygen to generate nitrogen oxides in a variety of forms. Its oxides have distinct oxidation states, ranging from +1 to +5. The oxidation state of nitrogen oxides with a higher oxidation state is more acidic than the oxidation state of nitrogen oxides with a lower oxidation state. Nitrogen oxides can be found in the following forms: 

• Dinitrogen oxide, N₂O
• Nitrogen monoxide, NO
• Dinitrogen trioxide, N₂O₃
• Nitrogen dioxide, NO₂
• Dinitrogen tetroxide, N₂O₄
• Dinitrogen Pentoxide, N₂O₅ 

Nitrogen dioxide, NO₂: 

NO₂ is an extremely deadly gas with the chemical name Nitrogen dioxide. It’s also known as nitrogen (IV) oxide or nitrogen dioxide. It is one among the most common contaminants in the atmosphere that absorbs UV radiation and prevents it from reaching the earth’s surface.

Nitrogen (IV) oxide is a yellowish-brown liquid or a reddish-brown gas that is compressed. When compared to air, its vapours are thicker. 

Sources of nitrogen dioxide: 

Combustion accounts for almost 98 percent of man-made N0 emissions, with stationary sources accounting for the majority. Combustion-generated nitrogen oxides are mostly exhaled as nitric oxide, or NO, a comparatively harmless gas that is quickly transformed to the lethal nitrogen dioxide in the atmosphere. Nitrogen dioxide has a negative impact on human respiratory functioning, and prolonged exposure can lead to a rise in respiratory illnesses. 

Properties of nitrogen dioxide: 

• Molar mass of NO₂ = 46.006 g/mol 
• Density of Nitrogen dioxide = 1.880 g/dm3 
• Boiling Point of Nitrogen dioxide = 21.15 °C 
• Melting Point of Nitrogen dioxide = −9.3 °C

Chemical properties of nitrogen dioxide: 

1. Thermal properties: Dinitrogen tetroxide gas exists in equilibrium: 

2 NO₂ ⇌ N₂O₄ 

1. As an oxidizer: NO₂ is a powerful oxidant due to the fragility of the N–O bond.
2. At low nitrogen dioxide concentrations, the process is negligibly slow. 
3. Formation of nitrites: Alkyl and metal iodides produce equivalent nitrites. 

2 CH₃I + 2 NO₂ → 2 CH₃NO₂ + I₂

TiI₄ + 4 NO₂ → Ti(NO₂)₄ + 2 I₂ 

Ecology of NO₂: 

NO₂ enters the environment by natural processes such as stratospheric entry, bacterial respiration, volcanoes, and lightning. NO₂ is a trace gas in the Earth’s atmosphere, where it absorbs sunlight and regulates the chemistry of the troposphere, particularly in determining ozone concentrations, thanks to these sources. 

Uses of nitrogen dioxide: 

1. In the manufacture of nitric acid, nitrogen dioxide is employed as an intermediary.
2. This chemical is used to make oxidised cellulose molecules.
3. As a catalyst, it’s used.
4. It’s a step in the process of making sulphuric acid.
5. Rocket fuels use it as an oxidizer.
6. As a nitrating agent, it is used.
7. Flour is bleached with it.
8. As an oxidising agent, it is used.
9. It’s used to make explosives. 

Environmental effects: 

Acid rain is formed when NO₂ and other NOₓ react with water, oxygen, and other chemicals in the atmosphere, causing devastation to vulnerable ecosystems like lakes and forests. Increased NO₂ levels can also affect vegetation, reducing growth and crop output. 

Avoiding NO₂ toxicity: 

When utilising a gas stove, it’s a good idea to employ ventilation as well. According to studies, children in households with gas stoves who employ ventilation when using gas stoves have a decreased risk of asthma, wheezing, and bronchitis than children in homes where ventilation is never used. If venting is not practicable, another option is to replace gas stoves with electric stoves. Replacement of gas stoves with electric ranges could considerably reduce indoor NO₂ exposure and enhance the respiratory function of asthmatic children. It’s critical to keep gas stoves and heaters in good working order so that they don’t emit additional NO₂. The 2015 International Residential Code mandates the use of vent hoods for all stoves and establishes criteria for residential structures. This necessitates the installation of an exterior vent on all range hoods. Avoiding cigarette smoking and not idling your car as much as possible can also help to reduce NO₂ exposure. 

Conclusion: 

At high quantities, nitrogen dioxide is an irritant gas that causes inflammation of the airways. NO₂ is mostly harmful to people who have respiratory problems that create a lot of inflammation in their airways. Long-term exposure reduces lung capacity, raises the risk of respiratory issues, and intensifies allergic reactions. NO₂ also leads to the creation of fine particles (PM) and ozone at ground level, both of which have negative environmental consequences.