When vapours of isopropyl alcohol are passed over heated copper, the major product obtained is

What happens when vapours isopropyl alcohol are passed over heated copper?

When vapours of secondary alcohol are passed over hot copper at 573K, the product formed is :

When vapours of tert.butyl alcohol are passed over hot copper, it gives ....

When excess vapour of ethyl alcohol are passed over heated alumina at 523K, the main product formed is

When the vapours of tert-butyl alcohol are passed through heated copper at 578 K, the main product formed is