Structure, Preparation, Physical Properties, Chemical Properties, and Uses - Nitrous Oxide , Dinitrogen Trioxide and Dinitrogen Pentoxide

Nitrogen oxides are extremely versatile! Some make you explode in laughter () and some end up making devil explosives ()! Some aid in ozone depletion () while some aid in making cloth fabrics like nylon and colourful dyes ()!

In fact, a single oxide can have such a wide range of properties! Just think of nitrous oxide. It can make you laugh as if you have got some great news! And also, the same nitrous oxide can contribute to the “not so good news” for humans on earth– ‘Ozone Depletion’!

Many substances deplete stratospheric ozone, the most well known being chlorofluorocarbons (CFCs), which are responsible for the Antarctic ozone hole. Nitrous oxide is another ozone-depleting chemical that has both natural and manmade sources. Furthermore, unlike CFCs, nitrous oxide’s usage and emission are not governed by the Montreal Protocol, which has aided in slowing the rate of ozone hole formation!

TABLE OF CONTENTS

Nitrous Oxide - Introduction
Nitrous Oxide - Oxidation State and Structure
Nitrous Oxide - Preparation
Nitrous Oxide - Properties
Nitrous Oxide - Uses
Dinitrogen Trioxide - Introduction
Dinitrogen Trioxide - Oxidation State and Structure
Dinitrogen Trioxide - Preparation
Dinitrogen Trioxide - Physical Properties
Dinitrogen Trioxide - Chemical Properties
Dinitrogen Trioxide - Uses
Dinitrogen Trioxide - Precautionary Handling Techniques
Dinitrogen Pentoxide - Introduction
Dinitrogen Pentoxide - Oxidation State and Structure
Dinitrogen Pentoxide - Preparation
Dinitrogen Pentoxide - Physical Properties
Dinitrogen Pentoxide - Chemical Properties
Dinitrogen Pentoxide - Uses
Practice Problems
Frequently Asked Questions - FAQ

Nitrous Oxide - Introduction

In the year 1772, Joseph Priestley was the first to discover nitrous oxide. Nitrous oxide () is a nitrogen oxide having the chemical formula . At ambient temperature, it is colourless as well as non-flammable. It is also known as ‘laughing gas’.

In 1799, ‘laughing gas parties’, or recreational inhalation of nitrous oxide with the goal of creating euphoria and/or minor hallucinations, became a craze for the British upper class.
It is also known as dinitrogen oxide, hyponitrous oxide and dinitrogen monoxide.
It is insoluble in water and at higher temperatures, acts as a potent oxidant.
It smells quite pleasant and seems like a colourless gas. It produces excitement and merriment once inhaled in very little amounts.
It is the world's most used inhaled anaesthetic because it relieves pain quickly. Consumption at greater doses can have possible narcotic effects and cause death by suffocation. Laughing gas is basically .

Nitrous Oxide - Oxidation State and Structure

Let the oxidation state of in be .

So,

∴

The structure of nitrous oxide can be represented as a resonance hybrid of the following structures:

Nitrous Oxide - Preparation

Ammonium nitrate on decomposition produces nitrous oxide.

When the temperature is over , the salt boils and begins to decompose, releasing nitrous oxide and water. Since cold water absorbs most of it, nitrous oxide has to be collected in a gasometer filled with water at about .

Nitrous Oxide - Properties

It is a stable and relatively unreactive gas.
It is colourless and a neutral oxide.
Its boiling point is and its melting point is .
Its molar mass is
Density is
Nitrous oxide reacts with sodium amide to form sodium azide, ammonia and sodium hydroxide.

Nitrous Oxide - Uses

It plays the role of an oxidiser in rocket motors.
It is utilised as a food ingredient and as a propellant for aerosol sprays.
It is a material utilised in the production of semiconductors.
It is used as an analgesic and anaesthetic in medicine.
It is employed as a flavouring agent.
It is a fuel additive in motor vehicles
It is used in dental procedures and treatments, and also to produce many chemicals.

Dinitrogen Trioxide - Introduction

Dinitrogen trioxide, is also known as N-oxonitramide, Nitrous anhydride, or nitrogen sesquioxide.

Only at low temperatures, i.e. in the liquid and solid phases, dinitrogen trioxide can be isolated.
It has a vivid blue colour in both liquid and solid phases.
It is a highly poisonous substance that irritates mucous membranes.
It is a blue liquid with an acrimonious, harsh odour.
At , it contains a long bond. It is a molecule with symmetry that is planar.
It partially dissociates into and .
It irritates the skin, mucous membranes, and eyes severely. Inhaling the vapours is quite dangerous.
It is frequently used in a variety of fuels.
The container containing dinitrogen trioxide may rupture violently and burst if exposed to heat for an extended period of time.

Dinitrogen Trioxide - Oxidation State and Structure

Let the oxidation state of in be .

So,

∴

Dinitrogen trioxide possesses a strangely longer bond of .

The hydrogen bond donor count in total is zero, while the total hydrogen bond acceptor count is four. The number of covalently bound units equals one in this compound, which is canonicalized. The molecular shape of this molecule is planar, with symmetry.

Dinitrogen Trioxide - Preparation

It can be produced by combining equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below .

At higher temperatures, with , the equilibrium shifts in favour of the constituent gases.

Dinitrogen trioxide can also be prepared by reacting with the appropriate amount of .

Dinitrogen Trioxide - Physical Properties

Boiling point: (dissociates).
Melting point: .
The chemical is retained as a liquid by compression due to its low boiling point. and are somewhat dissociated.
It is very much soluble in water and soluble in ether.
It is a polar molecule with a dipole moment of
The density of dinitrogen trioxide is .
The molecular weight of is .
It is a blue coloured solid.

Dinitrogen Trioxide - Chemical Properties

It is an acidic oxide of nitrogen. The oxidation state of in this compound is .
is an acid anhydride of nitrous acid which is an unstable acid. When combined with water, it creates the unstable nitrous acid ().

If the nitrous acid obtained is not removed or is used up quickly, then it decomposes to produce nitric acid and nitric oxide.
Salts of nitrite can be obtained when nitrogen trioxide reacts with bases.

Dinitrogen Trioxide - Uses

Dinitrogen trioxide is a strong oxidant.
As an oxidising agent, it is mixed with other chemical substances.
It is also used in the chemical sector to make nylon, dyes, and other products.
It is employed as a specific fuel because of its very explosive nature.
It merely aids in combustion and does not burn itself, potentially igniting objects such as wood, paper, oil, clothing, and other materials.

Dinitrogen Trioxide - Precautionary Handling Techniques

Fully encapsulating, vapour-protective clothes should be worn for non-fire spills and leaks.
Touching or walking over spilt material is not recommended.
Keep flammables away from the spilt substance (oil, wood, paper, etc.)
Stop the leak if you can without putting yourself in danger.
Use water spray to reduce vapours or deflect vapour cloud drift.
It is not a good idea to allow water runoff to come into contact with spilt substances.
The spill or the source of the leak should not be flooded.
If at all feasible, turn faulty containers so that gas escapes rather than liquid.
Access to rivers, sewers, basements, and other restricted areas should be controlled.
Isolate the area until the gas is no longer present.
Ensure the area is safely ventilated.

Dinitrogen Pentoxide - Introduction

The anhydrous form of nitric acid, dinitrogen pentoxide, can be found as a colourless crystal. Dinitrogen pentoxide is a somewhat unstable nitrogen oxide that is utilised as an oxidizer in a variety of chemical processes. It's a nitrating substance. Dinitrogen pentoxide is a volatile and possibly toxic oxidant that was once employed as a reagent for nitrations when dissolved in chloroform.

However, nitronium tetrafluoroborate () has mainly superseded it in recent years. Dinitrogen pentoxide is highly dissociated in nitric acid to provide a high concentration of nitronium cation. Dinitrogen pentoxide is a chemical that is unstable and mildly explosive but has little commercial value at the moment.

Dinitrogen Pentoxide - Oxidation State and Structure

Let the oxidation state of in be

So,

∴

is a salt that is made up of separated linear nitronium ions and planar trigonal nitrate anions . The oxidation state of both the nitrogen centers is .

The chemical occurs as covalently linked molecules () in the gas phase or when dissolved in nonpolar solvents such as carbon tetrachloride. The angle in each wing is around in the gas phase, and the angle is about 112°, according to theoretical estimates for the minimum-energy arrangement. The two groups are rotated around 35 degrees around the links to the central oxygen in that structure, away from the plane. As a result, the molecule bears a propeller form, with one axis rotating at 180 degrees.

The free radicals nitrogen dioxide ( and nitrogen trioxide () are formed when gaseous absorbs UV light. The absorption spectrum is broad, with the highest wavelength of .

Dinitrogen Pentoxide - Preparation

By properly dehydrating nitric acid with diphosphorus pentoxide or oxidising nitrogen dioxide with ozone, dinitrogen pentoxide can be synthesised as white crystals. It is an unstable chemical that decomposes spontaneously into nitrogen dioxide and oxygen at ambient temperature.

When a combination of oxygen and nitrogen is pushed through an electric discharge, dinitrogen pentoxide is produced.
The reaction of lithium nitrate () and bromine pentafluoride () in a ratio greater than 3:1 is another laboratory method to produce dinitrogen pentoxide.

Phosphoryl chloride () or nitryl chloride () interactions with silver nitrate () are another way of preparing dinitrogen pentoxide.

Dinitrogen Pentoxide - Physical Properties

It is a colourless, deliquescent solid.
It is an acidic oxide.
It is an anhydride of nitric acid ().
Its dipole moment is
It is soluble in chloroform, but its solubility is negligible in .
Its crystal is hexagonal.
It is soluble in water (Reacts to produce nitric acid)
Its density is
Its molar mass is
Its boiling point is (sublimes).
Its melting point is

Dinitrogen Pentoxide - Chemical Properties

Nitric acid is formed when dinitrogen pentoxide combines with water.

When dinitrogen pentoxide interacts with a base such as sodium hydroxide, sodium nitrate and water are formed.

Nitric acid () and nitryl chloride () are also produced by the reaction of with hydrogen chloride ().

At ambient temperature, dinitrogen pentoxide decomposes into and . If the solid is stored at in suitable inert containers, decomposition is minimal.
Between high temperatures of and , dinitrogen pentoxide decomposes in two stoichiometric steps:

Dinitrogen Pentoxide - Uses

In current synthetic organic chemistry, it is used as a nitrating agent. A nitrating agent made from a combination of and is also effective.
When the cell is occupied by the deteriorating nitrogen pentoxide and when the cell is occupied by the entirely decomposed nitrogen pentoxide, it is used to represent the light intensities transmitted.
In high-fuel rockets, it is used as a strong oxidizer.
Used in solvents that are not reliant on water to readily nitrate molecules that are extremely sensitive to water.

Practice Problems

Q. 1. Why is less basic than ?

Answer: As we move down the group, the atomic radius increase, the ionisation energy decreases, and the tendency to lose electrons increases (i.e., the metallic character is increased). As the metallic character increases, so does basicity.

Therefore, the basicity of is less than that if .

Q. 2. Find out the covalency of in .

Answer: Because three covalent bonds and one coordinate covalent bond exist in dinitrogen pentoxide, nitrogen has a covalency of four.

So, option B) is the correct answer.

Q. 3. Which is the anhydride of nitrous acid?

None of the above

Answer: is an acid anhydride of nitrous acid which is an unstable acid. When combined with water, it creates the unstable nitrous acid ().

So, option B) is the correct answer.

Q. 4. Various substances readily burn in the presence of nitrous oxide instead of air. This is because

The activation energy is increased on increasing temperature
It is reactive at very high temperatures
It can dissociate to give oxygen
Dissociated to form more nitrogen than in air

Answer: Nitrous oxide dissociates to form and as it is itself unstable. So it readily produces oxygen which is a supporter of combustion.

So, option C) is the correct answer.

Frequently Asked Questions - FAQ

Q 1. How long does the sedation effect of nitrous oxide last?

Answer: The sedative effect of nitrous oxide is felt quickly, and it wears off quickly once the gas is turned off. Sedation takes anything from 30 seconds to three or four minutes to take effect.

Q 2. What type of bonding is present in ?

Answer: It is composed of nitrogen and oxygen, both being non-metallic gases. Hence, they can form bonds only by sharing electrons. So, they have covalent bonding. In a covalent bond, electrons are shared between two molecules. An ionic bond occurs when one molecule accepts an electron from another, bringing them closer together.

Q 3. What are the health hazards related to dinitrogen trioxide?

Answer: Nitrogen sesquioxide () is a corrosive and poisonous substance. If inhaled or absorbed via the skin, it can be lethal. The chemical creates unpleasant, corrosive, and poisonous fumes when heated. When it comes into touch in its liquid form, it can cause serious harm and burns or bruises.

Q 4. What are the health hazards associated with dinitrogen pentoxide?

Answer: It can cause respiratory tract irritation, eye or skin infection upon exposure. is a powerful oxidant that reacts violently with organic molecules and ammonium salts, forming explosive combinations. The highly hazardous nitrogen dioxide gas is produced when dinitrogen pentoxide decomposes.

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