differentiate oxides of metals and non metals?

Answer 1

You will find that, as a general rule, oxides of metals are basic (and react with acids), while oxides of non-metals are acidic (and react with bases).

Answer 2

Chemical Concepts Demonstrated: Basicity of metal oxides, acidity of nonmetal oxides

Demonstration:

BaO is dissolved in water containing phenolphthalein.
The flask contains distilled water with bromothymol blue indicator already made blue by 0.1M NH3. The test tube contains chunks of dry ice. The flask and the test tube are connected with glass tubing as shown in the picture.
Red phosphorus is ignited and immersed in a flask of O2 gas. The P4O10 produced is dissolved in water that contains bromothylmol blue indicator already made blue by 0.1M NH3.


Observations:
1. The solution turns from colorless to pink.
2. As the CO2 is given off, the indicator changes from blue to green and then to yellow,
3. The solution turns from blue to green to yellow.

Explanations (including important chemical equations):

Metal oxides that dissolve in water react with water to form basic solutions.

BaO (s) + H2O(l) ---> Ba 2+(aq) + 2 OH - (aq)

Nonmetal oxides react with water to from acidic solutions.

CO2 (g) + H2O(l) ---> H2CO3 (aq)

P4O10 (s) + 6 H2O(l) ---> 4 H3PO4 (aq)

Answer 3

Lancenigo di Villorba (TV), Italy

Among former chemistry's foundaments, students learn that in oxidation processes :

METAL + w O2 --> Metal's OXIDE(s)
succeeded by
OXIDE(s) + x H2O --> BASE(s) ;

on the other hand, you learnt that :

NON-METAL + y O2 --> ANHYDRIDE(s)
succeeded by
ANHYDRIDE(s) + z H2O --> ACID(s)

where w, x, y, and z mean stoichiometric coefficients.
Did you named these scheme's oxidation? They derived by a french chemist (A. Lavoisier, XVIII century) who stated them.

Nonetheless, I want give you a contrary example : you would considerate TIN (e.g. Sn), a metal who produced several compounds (e.g. Sn(OH)2, Sn(OH)4). Among its oxidation's compounds there is one (e.g. Sn(OH)4) surely characterized by not-basic behaviour. Moreover, I say you that it is an water-insoluble compounds, hence it is not an acid versus water.

Strong HCl's aqueous solutions is a common solvent for distinguish oxidation's compounds of metals and non-metals, on basis of theirs chemical behaviours. In effect, trend of oxidation's compound of METALS is its conversion to salt's form (remember, you need a very very concentrated HCl's solution...also warm!!). So, chemical properties of metal's oxidation compounds are changed by dupping in hot strong acid's solutions. NON-METALS oxidation's compounds do not, they trend to remain unchanged.
Viceversa, a warm aqueous solution of strong bases (e.g. alkalies) can react with NON-METALS oxidation's compounds and hence you can remark change of theirs chemical properties (overcoming to salt's form for non-metals oxidation's compounds). In these conditions, trend of metals oxidation's compounds shows not alkaly's reaction, except several metals like Al, Zn, Pb, and Sn as overwritten...and some compounds of Cr or Mn whole do it.

I hope this helps you.