When ethanol vapours are passed over alumina heated at `350^(@)C` the main product obtained is

Ethyl alcohol vapour is passed over alumina heated at about 250^(@) . The major product formed in the reaction is

Ethyl alcohol vapour is passed over alumina heated at about 250^(@) . The major product formed in the reaciton is

Ethyl alcohol vapours when passed over alumina at 573K, the product obtained is

Isopropyl alcohol vapour is passed over alumina heated at about at about 240^(@)C . The product formed is-

Ethanol vapours are passed over heated copper at 300^(@) C and product is treated with aqueous NaOH. The final product is

When excess vapours of ethyl alcohol are passed over heated alumina (25^(@)C) , the main product formed is :