Preparation, Properties, and Uses of Dioxygen

Introduction

An oxidising agent that easily produces oxides with most elements and other compounds, oxygen is a member of the chalcogen group of the periodic table and a highly reactive nonmetal. Following hydrogen and helium in the order of abundance in the universe, oxygen is the element that is most plentiful on Earth. Currently, 20.95% of the atmosphere on Earth is made up of diatomic oxygen gas. Nearly half of the Earth's crust is composed of oxides, which are oxygen compounds. Oxygen is the chemical substance with the atomic number 8 and the letter 𝑂 in its name.

What is dioxygen?

With two oxygen atoms in the molecule, dioxygen is one of the most prevalent allotropes of elemental oxygen. whose chemical formula is 𝑂2. It is often referred to as oxygen, although it is also known as dioxygen, molecular oxygen, or oxygen gas to distinguish it from elemental oxygen. Ozone (𝑂3), one of the strongest oxidants known, is used to purify drinking water since it lacks the distinctive taste associated with chlorinated water. Apart from noble gases, practically every element reacts with oxygen gas. The resulting substance is known as oxides. The oxygen gas is necessary for combustion although it isn't flammable on its own. Mammals need oxygen to survive and because it helps with energy release, it is also a life-giving gas.

Like Groups 14 and 15, Group 16's lightest member has the greatest propensity to form multiple bonds. In this manner, elemental oxygen is discovered in the environment as a diatomic gas with the formula 𝑂 = 𝑂

Laboratory Preparation of Dioxygen

Dioxygen can be prepared in a lab in a variety of methods.

• When thermally broken down, oxygen-rich salts like nitrates and permanganates yield dioxygen.

$$\mathrm{2KNO_{3}\:\rightarrow\:2KNO_{2}\:+\:O_{2}}$$

$$\mathrm{2KMnO_{4}\:\rightarrow\:K_{2}MnO_{4}\:+\:MnO_{2}\:+\:O_{2}}$$

$$\mathrm{2NaNO_{3}\:\rightarrow\:2NaNO_{2}\:+\:O_{2}}$$

• Sodium potassium chlorate is catalytically broken down with magnesium dioxide to yield dioxygen

$$\mathrm{2KClO_{3}\:\rightarrow\:2KCl\:+\:3O_{2}}$$

• Dioxygen is produced during the thermal decomposition of electrochemical series metal oxides having relatively low electrode potential, such as mercury and silver oxides.

$$\mathrm{2HgO(s)\:\rightarrow\:2Hg(l)\:+\:O_{2}}$$

$$\mathrm{2PbO_{2}(s)\:\rightarrow\:2PbO(s)\:+\:O_{2}(g)}$$

• When hydrogen peroxide breaks down, oxygen is also produced, and manganese (IV) oxide is introduced as a catalyst to speed up the process.

$$\mathrm{2H_{2}O_{2}(aq)\:\rightarrow\:2H_{2}O(l)\:+\:O_{2}(g)}$$

Industrial preparation

A clean, dry air stream can also be used to produce dioxygen by running it over a zeolite molecular filter. After $\mathrm{N_{2}}$ gas has been absorbed, 90–93% of the supplied gas is oxygen.

• Oxygen is produced through water electrolysis as well. At the cathode, hydrogen is released, whereas, at the anode, oxygen is released.

• Oxygen can be separated by fractional distillation of liquified air. Water and carbon dioxide are first eliminated. After that, oxygen is left as a liquid and nitrogen gas $\mathrm{(N_{2})}$ is distilled as a vapour.

Properties of dioxygen

Physical properties

• Its molecular weight of it is 31.99 g/mol. Molar weight of 32 g/mol is employed for ease of use.

• It is very water-soluble (3.08𝑐𝑚3 in 100𝑐𝑚3 of water at 293K).

• It is an odourless gas with no colour.

• At -183 °C, it is a somewhat bluish liquid.

• It is denser than air due to its density of 1.429 g/L.

• Its boiling point is 182.962°C

• It has a 218.79°C melting temperature.

• It has a magnetic field (paramagnetic)

Chemical properties

Being a highly reactive element, oxygen reacts directly with practically all metals and non-metals. Some metals, including gold and platinum, as well as some noble gases, including helium, argon, and neon, don't react in an obvious way.

• So, most metals and nonmetals directly react with it to produce the corresponding element's oxides.

$$\mathrm{4Na\:+\:O_{2}\:\rightarrow\:2Na_{2}O(With\:Metal)}$$

$$\mathrm{C\:+\:O_{2}\:\rightarrow\:CO_{2}(With\:Non\:-\:metal)}$$

• Its nature is paramagnetic.

• Normally, acids and bases do not cause oxygen to react.

• Combustion is aided by oxygen since it is an effective oxidant.

$$\mathrm{Fuel\:+\:O_{2}\:\rightarrow\:CO_{2}\:+\:H_{2}O}$$

• The interaction of oxygen and humidity results in the production of rust on iron.

$$\mathrm{Fe\:+\:O_{2}\:+\:H_{2}O\:\rightarrow\:Fe_{2}O_{2}.nH_{2}O(Hydrayed\:Iron\:Oxide)}$$

Uses of dioxygen

• For respiration to take place, dioxygen is necessary.

• Liquid rocket fuel uses it.

• It is utilised for cutting and welding metals in the form of oxyacetylene.

• Nitric acid can be made using it.

• Hospital and mountaineering oxygen cylinders include it.

• Oxy-acetylene flames, which are used to cut and weld metal, are created when oxygen and acetylene gases interact.

• The methods of treating wastewater and sewage treatment both use oxygen to cleanse water.

• Ozone is used in laser cutting.

• Together with methane or carbon dioxide, it is employed in artificial respiration.

• Utilised in combustion processes is oxygen. Mixing oxygen and air promotes combustion because substances that do not typically combust in air burn readily in oxygen.

Conclusion

A highly reactive gas, oxygen has no colour, smell, or taste. On the crust of the Earth, it is not present in its purest form. It forms oxides with practically all metals and non-metals because of its strong electronegativity and reactivity. Oxygen-rich substances like barium peroxide, potassium chlorate, potassium permanganate, potassium nitrate etc. can be heated and broken down to create it. Peroxides and water can also be used to obtain oxygen. Dioxygen is combustible and paramagnetic. Hydrogen bonding is evident.

For life to continue on Earth, oxygen is a crucial component. It serves as the process' focal point. It is used for scuba diving, mountaineering, and filling artificial respiratory cylinders in hospitals. Oxygen has a wide range of commercial applications. It is crucial to the production of several metals, including steel, and the welding process.

FAQs

1. Why is sulphur a solid and dioxygen a gas?

Due to stronger interelectronic repulsions in small oxygen atoms, the 𝑂 − 𝑂 bond is weaker than the 𝑆 − 𝑆 bond. Additionally, because oxygen is more electronegative and smaller, it forms p–p multiple bonds. It, therefore, exists as molecules of oxygen held together by a negligible van der Waals force. At standard temperatures, oxygen is a gas. Sulphur is less likely to generate p-p multiple bonds than other elements. It also forms strong 𝑆— 𝑆 single bonds has a large atomic size, and a low electronegativity, which accounts for its increased catenation and existence as 𝑆8 molecules with a puckered ring shape. Sulphur is a solid as a result at room temperature.

2. How exactly is ozone created?

By using a unique apparatus, we can create ozone by quietly discharging an electric current through cold, dry, and pure oxygen. What is commonly referred to as an ozonised is this gadget. We can produce gas with a 10% concentration with this procedure.

3. When alkali metal and oxygen react what happens?

Alkali metals and oxygen react very quickly (Group I elements). Keep alkali metals far from oxygen to prevent oxidation. The group's bottom-most metals are much more reactive than its top-most metals. The lighter alkali metals produce superoxide, and $\mathrm{MO_{2}}$, while lithium and sodium produce monoxides, $\mathrm{Li-[2]O}$ and $\mathrm{Na_{2}O}$, respectively.

4. Is dioxygen regarded as a compound or a molecule?

It has two oxygen atoms that are bound together by a covalent connection, making it a diatomic molecule.

5. Dioxygen is a gas with blue colour and is not crucial for life. Is it real or not?

The diatomic gas classified as dioxygen gas is the kind of oxygen that we breathe. This is a gas which has no flavour, no smell, and no colour. It is necessary for life to survive because it is used by plants and animals during metabolism, which burns down food components to create energy. Therefore, the statement is false.