Determine which compound is more soluble in water for each of the following pairs (i): CH₃OCH₃ or CH₃CH₂CH₃, (ii): CH₃OCH₃ or CH₃CH₂OH, (iii): CH₃NHCH₃ or CH₃CH₂CH₃, (iv): CH₃OH or CH₃CH₂CH₂OH, (v): butanone or cycloheptanone.