(i) Cinnamaldehyde - (d) 3-Phenylprop-2-enal

(ii) Acetophenone - (e) 1-Phenylethanone

(iii) Valeraldehyde - (a) Pentanal

(iv) Acrolein - (b) Prop-2-enal

(v) Mesityl oxide - (c) 4-Methylpent-3-en-2-one

EXPLAINATION:

i) The structure of Cinnamaldehyde is:

Here, a phenyl group is attached to a carbon atom at 3^rd position with respect to the functional group. A double bond is present between the C₂ and C₃ atoms. Thus, the IUPAC name of Cinnamaldehyde is 3-Phenylprop-2-enal.

ii) The structure of Acetophenone is:

Here, the functional group present in the above structure is ketone. This ketone group is attached to one methyl group and one phenyl ring.

Thus, the IUPAC name of Acetophenone is 1-Phenylethanone.

iii) The structure of Valeraldehyde is:

CH₃CH₂CH₂CH₂CHO

The functional group in this compound is aldehyde. The number of carbon atoms in the longest chain is five. Thus, the IUPAC name of Valeraldehyde is Pentanal.

iv) The structure of Acrolein is:

CH₂=CH-CHO

The functional group in this compound is aldehyde. The number of carbon atoms in the longest chain is three with one double bond between C₂ and C₃ atoms. Thus, the IUPAC name of Acrolein is Prop-2-enal.

v) The structure of Mesityl oxide is:

(CH₃)₂C=CHCOCH₃

The functional group in this compound is ketone. The number of carbon atoms in the longest chain is five with one double bond between C₃ and C₄ atoms. Thus, the IUPAC name of Mesityl oxide is 4-Methylpent-3-en-2-one.