hmm....i wrote that it was aluminium oxide which due to heat turned black. because they asked what was the substance x. u could easily see that it was a solid so i don't think it could have been H2SO4. and Al2O3 also helps to dehydrate alcohol to alkene. i read that some where. but i wasn't sure about that removing out of water thing......and guys for the last part of the last question the organic product should have been CH3COOH right?