Dinitrogen Chemical Reactions: introduction, Preparations, Physical Properties, Chemical Reactions and Uses of Dinitrogen, Practice Problems & Frequently Asked Questions(FAQs)

Once every fuel station used to provide free air filling for the automobile tyre tubes. But nowadays,they have compressed nitrogen gas instead of compressed air. Getting compressed nitrogen gas is costlier than compressed air. After all it is to fill the gap inside the tubes and make the vehicle lighter to move. Then why should we fill up nitrogen instead of cheap air?

Nitrogen gas has many advantages than air to fill the automobile tubes. Auto tyres loaded with nitrogen perform much better than tyres loaded with compressed air. Nitrogen can be added to your car's tyres to improve fuel economy. Since nitrogen is harder to remove from a tire's cavity than compressed air is, the pressure inside the tyre remains stable for a considerable amount of time. When the pressure is ideal, the car's engine operates more smoothly.

Nitrogen can increase the tyre longevity and fuel economy of your car. The wheels rust as a result of the water vapour in pressurised gas. Nitrogen, on the other hand, lessens the likelihood of corrosion and increases tyre longevity.

Additionally, nitrogen-inflated tyres offer more security than pressurised air-inflated tyres. No matter the weather, nitrogen-inflated tyres are the best choice. These tyres promise consistent performance in both dry and wet conditions. If you frequently drive on highways, nitrogen-filled tyres will help you enhance your driving experience and smooth the ride.

Table of Contents:

• Introduction of Dinitrogen
• Preparations of Dinitrogen
• Physical Properties of Dinitrogen
• Chemical Reactions of Dinitrogen
• Uses of Dinitrogen
• Practice Problems
• Frequently Asked Questions(FAQs)

Introduction of Dinitrogen:

Daniel Rutherford, a Scottish scientist, invented nitrogen in 1772. Lavoisier gave the name azote. The name nitrogen is derived from the well-known nitrogenous compound nitre that contains nitrogen. Nitrogen is the the first element in group 15 of the periodic table and has the electronic structure of 1s2 2s2 2p3. Nitrogen exists as diatomic and N2 is used to denote nitrogen in molecules. All animal and plant proteins, as well as all biological activities, need the element nitrogen.

A diatomic molecule with a triple bond is the nitrogen molecule. Its bond enthalpy is quite high as a result. Nitrogen has a weaker affinity for catenation than P-P because of its short bonds and high interelectronic repulsion of non-bonding electrons. The ability of nitrogen to generate many p-p bonds with itself makes it special. Due to a lack of empty d-orbitals, nitrogen can only have a maximum covalency of four. Nitrogen cannot create a d-d bond as a result.

Isotopes of Nitrogen:

The two naturally occurring nitrogen isotopes, nitrogen-14 and nitrogen-15, can be separated via thermal diffusion or chemical processes. Additionally, there exist radioactive nitrogen isotopes with 12, 13, 16, and 17 masses.

With over 99 percent of the nitrogen that occurs on Earth is in the form of nitrogen-14, which is also the most common type. It is a stable, non-radioactive substance. Agriculture, food preservation, biochemicals, and medicinal research are nitrogen-14's most beneficial uses. Substantial levels of nitrogen-14 are present in both the atmosphere and several living beings. It possesses five valence electrons.

Nitrogen-15 is the other well-known isotope of nitrogen. It is extensively used for medical research and preservation. The chemical can occasionally be used in agricultural procedures because it is non-radioactive.

Preparations of Dinitrogen:

1. Sodium nitrite reacts with an aqueous solution of ammonium chloride to produce dinitrogen.

NH₄Cl(aq) + NaNO₂(aq) → N₂(g) + 2 H₂O(l) + NaCl(aq)

2. Thermal decomposition of ammonium dichromate releases nitrogen gas..

NH₄Cr₂O₇(s) + Heat → N₂(g) + 4 H₂O(l) + Cr₂O₃(s)

3. Very pure nitrogen is produced by the thermal decomposition of barium or sodium azides.

Ba(N₃)₂ → Ba+ 3 N₂

4. Liquefaction and fractional distillation of air are steps in the commercial production of dinitrogen. After the liquid dinitrogen is separated, liquid oxygen is left behind. .

Physical properties of Dinitrogen:

• Dinitrogen is a harmless gas that has no colour, taste, or odour.

• It has a low boiling point, low freezing point, and very little water solubility.

• Dinitrogen is chemically unreactive at room temperature due to the superior bond enthalpy of the N–N bond.

• On the other hand, as the temperature goes up, reactivity rises rapidly. When it interacts directly at elevated temperatures with some metals, it primarily creates ionic nitrides; when it interacts with nonmetals, it primarily forms covalent nitrides.

• A colourless liquid of nitrogen condenses into a mass that resembles snow after solidifying.

• N2 is essentially non-reactive at room temperature. Because of the triple bond and high molecular stability, N2 is chemically inert at room temperature.
• It neither burns and not a supporter of combustion

• It has been observed to react with metals including calcium, lithium, and alkali metals at incredibly low conditions.

Chemical Reactions of Dinitrogen:

1. Reaction with Electropositive Metals:

It forms nitrides when heated up in combination with a few highly electropositive metals. Lithium nitride forms gradually at low temperatures but rapidly at high temperatures. Magnesium and aluminium continue to burn and produce nitrides in the presence of nitrogen. When heated to a high temperature, calcium, strontium, and barium also react with N2 .

6 Li + N₂ → 2 Li₃N

3 Mg + N₂ → Mg₃N₂

2 Al + N₂ → 2 AlN

3 Ca + N₂ → Ca₃N₂

2. Reaction with Oxygen:

Nitric oxide is created when N2and O2 combine in an electric arc (above 3273 K).

N₂ + O₂ → 2 NO

This is a natural phenomenon occurring in the atmosphere during lightning.

3. Haber’s process:

At 725 K and 200 atmospheres of pressure, N₂ and H₂ react in the presence of a catalyst (finely divided iron and molybdenum). This is known as Haber's process.

N₂ + 3 H₂ → 2 NH₃

Ammonia production is a very important and high volume chemical worldwide needed for the preparation of fertilisers.

4. Reaction with Alumina:

Carbon monoxide and aluminium nitride are produced when nitrogen and alumina react in the presence of coke.

Al₂O₃+ N₂ + 3C → 2 AlN + 3 CO

5. Reaction with Calcium Carbide:

Calcium cyanamide is the product of the reaction between calcium carbide and nitrogen.

CaC₂ + N₂ → CaCN₂+ C

Uses of Dinitrogen:

• Instead of air, potato chip bags are filled with nitrogen gas. This prevents the chips from oxidising, which is one of the factors that contributes to their staleness.

• Chemical reactions are sparked by oxygen's high reactivity and propensity to combine with other molecules whenever it can.

• To avoid rancidity is another reason. The oxidation of fats and oils is stopped by nitrogen.

• To accurately conduct experiments and record results, scientists and researchers need a specific environment in laboratories. Nitrogen is used to control moisture, temperature, and oxygen saturation in order to achieve this. The gas helps to maintain the ideal conditions required for delicate procedures and tests with large machinery in this way. In addition, nitrogen is required for purging in a wide variety of lab equipment.

• Nitrogen has become an important factor for the entire steel industry due to its purging capabilities. Molten residue is blown away with nitrogen gas to produce a stronger, more resilient, and corrosion-resistant stainless or aluminized steel product.

• The primary use of N₂ is in the formation of ammonia. It is also used to make a few other important chemicals, such as calcium cyanamide and nitric acid.

• In potentially explosive chemical plants, manufacturers regularly use nitrogen to replace oxygen. It is frequently used to stop fires and explosions in hazardous environments like factories, production facilities, and chemical plants. By lowering the oxygen level, one can prevent explosions in their production facilities.

Practice Problems:

Q1. Electric bulbs are used to be filled with nitrogen because:

(A) It is not harmful.
(B) It is not suitable for combustion.
(C) It illuminates the bulb.
(D) All of the above

Answer: (B)

Solution: The exceptionally hot tungsten filament would burn up quickly in the oxygen of an electric bulb if it were filled with air. So, an inert gas such as argon or nitrogen is used to fill the electric bulb. Because these gases do not react with the hot tungsten filament, the filament of the light bulb lasts longer.

Q2. Ammonia (NH₃) is

(A) Lewis Base
(B) Lewis Acid
(C) Both A and B
(D) None of the above

Answer: (A)

Solution: The central metal atom in the ammonia molecule is a nitrogen atom. Since nitrogen has a lone pair of electrons that can be donated, ammonia functions as a Lewis base. Protons can receive a single pair of electrons from NH3 to create ammonium ions. The Lewis base tendency is evident in the following reaction

NH₃ + H+ → NH₄⁺

The lone electron pair on the nitrogen atom is transferred to the hydrogen ion in this reaction. Here, the hydrogen ion functions as a Lewis acid, accepting electrons from the ammonia.

Q3. Which group is meant by the term "pnicogens"?

(A) Group 13
(B) Group 15
(C) Group 15
(D) Group 18

Answer: (B)

Solution: The "pnicogens" are a more popular name for the periodic table's group 15. The word pnicogen implies "to choke." Since all of the elements in this group are choking by nature, including nitrogen's choking characteristic.The Boron group is referred to as Group 13. The carbon group is known as group 14.Chalcogens are the name for Group 16.

Q4. Which nitrogen oxide is released by gasoline engines?

(A) NO₂
(B) NO
(C) N₂O
(D) N₂O₄

Answer: (B)

Solution: The fuel burns with air to form carbon oxides and water. The reaction is exothermic and hence the gasoline engine will be very hot. At the high temperature, nitrogen and oxygen present in the air combine ot form nitric oxide.

N₂(g) + O₂(g) → 2 NO(g).

NO (Nitric oxides) gas can undergo further oxidation to NO₂ (Nitrogen dioxide), in the atmosphere. Nitrogen dioxide dissolves in water during rain, to form nitric acid and cause acid rain.

Frequently Asked Questions(FAQs)

Q1. What is Nitrogen Fixation?
Answer: Microbes and blue-green algae are principally responsible for nitrogen fixation, which is the process of transforming nitrogen gas into inorganic nitrogen molecules.

As a result of nitrogen fixation, nitrates and ammonia are produced, and these substances are then embedded into the specific tissue parts of algae and higher plants. These plants and algae are consumed by animals, who then transform them into the components of their own bodies.

Q2. Why does nitrogen lack allotropy?
Answer: Nitrogen does not show allotropy because it is both small in size and highly electronegative. The single N-N bond is relatively weaker than the P-P bond because of powerful interelectronic repulsions between non-bonding electrons caused by the short bond distance. It doesn't show allotropy as a result.

Q3. Why is nitrogen's covalency four?
Answer: Covalency is the maximum number of electrons that an atom can share in forming chemical bonds. Usually, it refers to the number of covalent bonds the atom can form. The nitrogen atom can share up to four electrons, with one of those electrons being in the s-subshell and the other three being in the p-subshell. Its covalency is also restricted to four due to the lack of d-orbitals.Eg Ammonium ion

Q4. What happens when the nutrients are excessive in lakes?
Answer: The natural process of eutrophication is brought on by the buildup of nutrients in lakes and other bodies of water. Nutrient-feeding algae develop into unhygienic filth on the water's surface, reducing its value for recreation and blocking up inlet pipes. Decomposing mats of dead algae can leave the water tasting and smelling bad; bacteria feed on this dissolved oxygen, sometimes leading to fish kills. By accelerating the rate at which nutrients enter the water, human activities can speed up eutrophication.

A water body is said to be nitrogen confined if the ratio of nitrogen species to phosphorus species (N:P) is lesser or phosphorus limited if N:P is higher. Algal growth is typically restricted by the amount of available phosphate or nitrate.

Nutrient enrichment can cause harmful algal blooms (HABs), which can be brought on by a variety of different types of algae in freshwater systems. The only freshwater algae known to have the capacity to produce toxins strong enough to endanger human health, cyanobacteria, are typically responsible for the most frequent and severe blooms. Both human and aquatic ecosystem health are at risk from cyanoHABs. The loss of recreational revenue, falling property values, and rising costs of drinking-water treatment are just a few examples of the economic harm caused by cyanoHABs.