Ethanol can be converted into ethene which can be changed into ethane. Choose the correct word or phrase from the brackets to complete the following sentences.
(a) The conversion of ethanol into ethene is an example of (dehydration, dehydrogenation). (b) Converting ethanol into ethene requires the use of (conc. HCl, conc. HNO3,conc.H2SO4). (c) The conversion of ethene into ethane is an example of (hydration, hydrogenation). (d) The catalyst used in the conversion of ethene into ethane is commonly (iron, nickel, cobalt).