Answer :
ethanol is dehydrated and it forms ethene gas. sulphuric acid acts only as a catalyst. the water produced from the reaction gets mixed with sulphuric acid and it gets diluted.
C2H6OH ----------------------- > C2 H4 + H2 O
excess of H2SO4 & high temperature 443K
C2H6OH ----------------------- > C2 H4 + H2 O
excess of H2SO4 & high temperature 443K