The context provides the direct answers for all four parts of Question 7.12. For parts (i), (ii), and (iv), the ethers undergo cleavage with hydrogen halides (HBr or HI) to form corresponding alcohols and alkyl halides. For part (iii), the ethoxy group activates the benzene ring towards electrophilic substitution and directs the incoming nitro group to ortho and para positions, as mentioned in the context regarding aryl alkyl ethers.