How many alkene/s react faster than propene with dil `H_(2)SO_(4)`?

Ethoxy ethane with dil. H_(2)SO_(4) gives

Why aluminium does not react with dil H_(2)SO_(4) ?

The intermediate compound formed when acetylene s hydrated in presence of dil H_(2)SO_(4) and HgSO_(4) is

Which is not decomposed by dil. H_(2)SO_(4) ?

How many alkene/s from following are more stable than