An amphoteric oxide is an oxide which in a reaction can act either as an acid or as a base to produce salt and water. Amphoterism is the basis of the oxidation states available to a chemical species. When metals have several states of oxidation, amphoteric oxides and hydroxides are formed. An oxide is called amphoteric oxide if an oxide reacts with an acid and forms a salt or if an oxide reacts with a base that forms a salt.
In combustion processes, nitrogen oxides are formed, partly from nitrogen compounds in the fuel, but mostly through the direct combination of atmospheric oxygen and nitrogen in flames. Naturally, nitrogen oxides are formed by lightning, and also, to a small degree, by soil microbial processes. Significant sources of oxides of nitrogen are the exhaust gases of cars and trucks, as are the emissions from electrical power generation plants. Automotive exhaust has more NO than NO2, but it easily mixes with oxygen in the air to form NO2 until NO is released into the atmosphere.
How to Identify Amphoteric Oxides
Basic oxide is the oxide that provides a base in water. An amphoteric solution is a compound that can react as either acid or base chemically. It is also true, however, that an oxide is neither acidic nor fundamental, but is a neutral oxide.
Amphoteric oxides, some of the d-block elements, and the heavier elements of Groups 14 and 15 are found in the lighter elements of Groups 2 and 13. When a substance reacts chemically, it is called an amphoteric solution, whether as a base or an acid.
Amphoteric compounds may be detected by removing hydrogen ions repeatedly from the acid or by adding hydrogen ions to the base repeatedly. NO2– is not amphoteric because it’s not an acid, it has no more hydrogen ions than can be extracted, let alone more hydrogen ions.
Nitrogen Oxides Examples
Nitrogen is colourless, odourless in its gas form, and usually known to be inert. Nitrogen is also colourless and odourless in its liquid form, and, according to Los Alamos, appears similar to water. During combustion, nitrogen oxides are created from the reaction of nitrogen and oxygen gases in the air, especially at high temperatures. Oxygen and nitrogen gases don’t react together at normal temperatures. Nitrogen oxides are produced from a lightning strike, naturally.
Only three of the five nitrogen oxides, namely nitrogen dioxide (NO2), nitric oxide (NO) and nitrous oxide (N2O), are substantially present in the atmosphere the other two nitrogen oxides are nitrogen trioxide (NO3) and nitrogen pentoxide (N2O5).
If a burning wooden splint or piece of paper is put into a gas tube and the fire goes out immediately, then nitrogen versus oxygen is the gas. If a wet pH paper is inserted into a gas tube and there is no improvement, then nitrogen is the gas versus carbon dioxide.
Nitrogen dioxide is a corrosive agent that, upon contact with water, forms nitric and nitrous acids; it is more acutely toxic than nitric oxide, even when nitric oxide can kill more rapidly at lethal concentrations.