Give simple chemical test to distinguish between the following pairs of compounds.
i. Propanal and Propanone
ii. Acetophenone and Benzophenone
iii. Phenol and Benzioc acid
iv. Benzoic acid and Ethyl benzoate
v. Pentan-2-one and Pentan-3-one
vi. Benzaldehyde and Acetophenone
vii. Ethanal and Propanal