Profile
Settings
Refer your friends
Sign out
About Oxygen
Oxygen is a very reactive element that is abundant on Earth as well as in the human body. It can be found in various compounds that are vital to the survival of basic life forms and modern civilisation. Oxygen-containing compounds are of respective interest in the chemistry’s field.
Chemical reactivity
The likelihood of intensity with which an atom reacts with other substances is called reactivity. Because chemical processes rely on electron transfer/interaction, this is primarily defined by the ease with which electrons can be removed (ionisation energy) and the urgency with which they want to take the electrons of other atoms (electronegativity).
Metal’s reactivity decreases over time as you move from left to right.
The higher the reactivity, the easier it is for electrons to be given or taken away as you move further to the left and down the periodic table.
Non-metals – Reactivity increases as we move from left to right. As we move through the group, our response rate decreases. The greater the electronegativity, the more active the electron exchange. The higher the electronegativity, the higher we move up and to the right on the periodic table.
The chemical reaction of oxygen
When an oxide reacts with water, metal hydroxide is formed. Alkali metals with oxygen have a high degree of reactivity. The name alkali metal comes from the fact that their oxides react with water to form a basic or alkaline metal hydroxide. Gold and platinum are mostly inert in the presence of oxygen.
Chemical properties of alkali metals
Because alkali metals are very electropositive (least electronegative) of all elements, they react with many nonmetals. In terms of chemical reactivity, lithium is more similar to group 2 (IIA) of the periodic table than the other metals in its own group. It is quite less reactive with water, oxygen, and halogens than the other alkali metals, but more reactive with nitrogen, carbon, and hydrogen.
Reactions of alkali metals with oxygen
Alkali metals are prone to the formation of ionic solids with an oxidation number of +1. As a result, based on the oxygen species involved, neutral oxygen-containing substances can be easily classified. Oxide(O2–), peroxide(O22-), superoxide( O2–), and ozonide(O3–)are all ionic oxygen species. Monoxide(M2O), peroxide(M2O2), superoxide( MO2), and ozonide(MO3) are all compounds that can be made with an alkali metal, M, and oxygen. M4O6, a sesquioxide with two peroxide anions and one superoxide anion per formula unit, is also formed by rubidium, cesium, and possibly potassium. Only monoxide and peroxide are produced by lithium. All alkali metals react directly with oxygen, producing monoxides (Li2O and Na2O) in the case of lithium and sodium and superoxides (MO2) in the case of the heavier alkali metals. The rate of reaction with oxygen or air is influenced by the metals’ solidity or liquidity, as well as the degree of mixing between the metals and the oxygen or air. Alkali metals are easily ignited in the air when they are liquid, producing enormous amounts of heat and a dense choking cloud of the oxide. At 25 °C (77 °F), the free energy of production (a measure of stability) of alkali metal oxides ranges from 133 kcal/mole for lithium oxide to 63 kcal/mole for cesium oxide. The small lithium ion’s close proximity to the oxygen atom accounts for the oxide’s high free energy of formation. Although sodium peroxide is commercially produced by oxidising sodium monoxide with oxygen, the peroxides (Li2O2 and Na2O2) can also be produced by passing oxygen through a liquid ammonia solution of an alkali metal.
Reactions with group 1 elements
When it comes to group 1 elements, oxygen is the most reactive. When alkali metal oxides are dissolved in water, they all produce basic solutions. The main combustion product is the most stable of the reactants. By carefully controlling oxygen, the oxide M2O (where M represents an alkali metal) can be produced with an alkali metal. Lithium, sodium, potassium, rubidium, and cesium ignite when heated due to oxygen combustion processes.
The first metal in group 1 is lithium, which, when combined with oxygen, produces Li2O and burns with a red flame. The oxygen in this compound is an oxide (O2–). However, if there is an excess of oxygen present, a trace amount of Li2O2 may form. Oxygen is always in the O22- state because alkali metals have a +1 oxidation state. When oxygen is in this state, a chemical called peroxide is formed.
When sodium burns in the air, it gives off a faint orange glow—increasing the sodium content or burning it in pure oxygen results in a powerful orange flame. As a result, a white solid sodium oxide/sodium peroxide mixture is formed.
Potassium – When small amounts of potassium are heated in the air, they quickly transform into a mixture of potassium peroxide and potassium superoxide with no visible flame. Larger pieces of potassium emit a lilac-coloured flame.
Alkali metals that are not alkali metals, The other alkali metals (Rb, Cs, and Fr) produce superoxide compounds as primary combustion products (oxygen in the form of O2-). O2- has a high affinity for another electron because it is one electron short of completing an octet, making these compounds excellent oxidising agents. It can be used as an oxidising agent because it is easily reduced.
The chemical reaction of metal with oxygen
When a metal reacts with oxygen, a metal oxide is formed. The simple equation for this reaction is metal + oxygen = metal oxide. When iron is exposed to air, it forms rust, a type of iron oxide.
Oxides are formed when metals and nonmetals are burned in oxygen. Non-metal oxides have an acidic character, whereas metal oxides have a basic one.
Example
Mg (Magnesium) + O₂ (Oxygen ) → 2MgO (Magnesium Oxide (Basic))
S (Sulphur) + O₂ (Oxygen) → SO₂ ( Sulphur dioxide (acidic)
Nitric oxide and oxygen reaction
When nitric oxide is exposed to oxygen, it is converted to nitrogen dioxide: 2NO + O₂ → 2 NO. This reaction is thought to involve the intermediates ONOO• and the red complex ONOONO. Nitrous acid is formed when nitric oxide reacts with oxygen in water (HNO2).
The reaction of nitric oxide (NO) with oxygen to produce nitrogen dioxide (NO2) is a critical step in the formation of photochemical smog: 2NO(g)+O₂ (g)⟶2NO₂ (g).
Conclusion
A metal oxide is formed when a metal reacts with oxygen. Metal + oxygen → metal oxide is the general equation for this reaction. When iron is exposed to air, it develops rust, which is a form of iron oxide. Metal oxides have a basic character, while non-metal oxides have an acidic one.
