How can the reaction with oxygen be used to distinguish a metal from a non-metal?

Answer 1

A reaction with a metal and oxygen will create a metal oxide that is basic in water.

Ex. 2Mg + O2 —> 2MgO

MgO + H20 —> Mg(OH)2

Mg(OH)2 is basic.

The opposite is true for non-metals. When a non-meteal and oxygen react, they make a non-metal oxide that tend to be acidic oxides.

Ex. C + O2 —> CO2

CO2 + H2O —> H2CO3

H2CO3 is carbonic acid

Thus by determining whether the compounded created (with oxygen) is acidic or basic, you can distinguish a metal from a non-metal.

Answer 2

Metals will burn in the presence of oxygen to produce a metal oxide. Science teachers generally demonstrate this process by setting a small strip of Magnesium on fire. It burns quickly with a bright, white flame.

Non-metals such as silicon do not undergo this type of oxidation reaction and are generally non-reactive in the presence of oxygen.

Answer 3

Both metals and non-metals will generally react with oxygen and become what we call 'oxidized'. The difference is that metals react with oxygen to create alkaline, or basic, oxides while non-metals react with oxygen to create acidic oxides.

Metal example: 2Mg + O2 --> 2MgO

When magnesium oxide (MgO) is added to water, it accepts a proton (really it donates an electron pair) and magnesium hydroxide is created. By both the Lewis and the Bronsted-Lowry definition of acids and bases, MgO is a base.

Non-metal example: SO2 + H2O --> H2SO3

H2SO3 is known as sulfurous acid. By all definitions of acids and bases, H2SO3 almost always acts as an acid.

You will see this common trend when oxidizing metals and non-metals, so the oxidation process can easily be used to distinguish between a metal and a non-metal.

Answer 4

Metals react with oxygen to form basic oxides, which will dissolve through reaction with acids such as hydrochloric and, depending on degree of water solubility, will also provide a pH response of greater than 7.

Nonmetals react with oxygen to form acidic oxides which will react with bases such as sodium hydroxide and also provide a pH response of less than 7.

Aluminum oxide (AL2O3) is amphoteric, meaning that it will react with both strong acids and bases