You will notice that the copper oxide present in the beaker dissolve 51/306 in dilute HCl and the colour of the solution becomes blueish-green. Th reason for this change is the formation of copper (II) chloride in the reaction. The general reaction between a metal oxide and an acid can be written as:
Metal oxide + Acid→Salt + Water
Write the chemical equation for the reaction between copper oxide and HCl and balance it.
In above reaction metal oxide reacts with acid to give salt and water This reaction is similar to the reaction of a base with an acid that we have observed in activity-5.
In both the reactions salt and water are the products. Both metallic oxides and metallic hydrides give salt and water when they react with an acid. Thus we can conclude that metal oxides are basic in nature like the metal hydroxides.
You saw the reaction between carbon dioxide and calcium hydroxide (lime water) in activity-4, Calcium hydroxide, which is a base, reacts with carbon dioxide to produce a salt and water. This reaction is similar to the reaction between a base and an acid. Thus we can conclude that carbon dioxide which is a non metal oxide is acidic in nature. In general all non-metal oxides are acidic in nature.
What do acids have in common?
In previous sections you have seen that acids have similar chemical properties. In lab activity you have observed that acids generate hydrogen gas on reacting with metals, so hydrogen seems to be common element to