Question: I read that:

> 
> Take a cupful of water in a beaker and add a few drops of dilute
>  sulfuric acid. Heat the water. When it starts boiling add copper
>  sulfate powder slowly while stirring continuously.
>  Continue adding copper sulfate powder till no more powder can be
>  dissolved. Filter the solution. Allow it to cool. Do not disturb the
>  solution when it is cooling. Look at the solution after some time. Can
>  you see the crystals of copper sulfate? If not, wait for some more
>  time.
> 
> 
> 

So why is sulfuric acid required in this experiment?

Answer: 
Pi bonds involve sideways overlap while sigma bond involves head on or axial overlap. Axial overlaps have higher degree of overlapping than sideways overlap.
Unsaturated compounds (due to the existence of a double bond) are more reactive than saturated compounds, because the electron density at the internuclear axis is zero in a pi bond (in contrast to the sigma bond).