Tag: properties of acids and bases

Metal oxides always reacts with acid to form salt and water. Copper oxide when reacts with $HCl$ it forms blue-green copper(II) chloride. 

The non-metal oxides can be neutralized with a base to form a salt and water.

Sulphur, nitrogen and phosphorus are non-metals and form non-metallic oxides. $H _2SO _4$ is an acid. 

$H _2SO _4 + CuO \rightarrow CuSO _4 + H _2O$

Only carbondioxide reacts with base to form salt and water. Carbon monoxide does not give this reaction. 

Aluminium oxide is an amphoteric oxide. It can react with both with an acid and a base to form salt and water. 

$CuO + 2HNO _3 \rightarrow Cu(NO _3) _2 + H _2O$

When magnesium oxide reacts with $HCl$, it gives salt and water
$\displaystyle MgO + 2HCl \rightarrow MgCl _2 + H _2O$

When $HCl$ reacts with copper oxide, the black color of copper oxide turns blue due to formation of its corresponding salt i.e. calcium chloride. Water is formed along with salt.

Generally, more metallic character of an element represent, formation of more basic oxide. Likewise, the more non-metallic character an element has, the more acidic oxide. The metallic character of an element can be determined by its position on the periodic table.