Answer
See explanation
Work Step by Step
a) The given compound is not possible because according to the given name Cl group is present in C2 position but C2 Carbon already bonded with C1 with a single bond and C3 carbon with a triple bond. So, there is no bond remaining at C2 position.
b) Here C2 carbon is bonded with O by double bond and bonded with C1 and C3 carbon by two single bonds respectively. So, there is no bond remaining at C2 position. So, methyl group cannot be present as a substituent at C2 position.
c) In benzene ring every C atom is attached with 2 adjacent C atoms, one with single bond and other with double bond. So, the remaining bond is attached to one 'H' atom. so, only one atom/group of atoms can be substituted in place of H. But the given compound has two methyl group in C1 position which cannot be possible.
d) 'anal' stands for aldehyde (-CHO) which is a terminal functional group i.e. the C atom of the group will always get number 1 while numbering the C atoms in straight chain. But here we see that it is at C2 position which is not possible.
e) 'anoic acid' stands for Carboxylic acid group which is also a terminal group i.e. the C atom of the group will always get number 1 while numbering the C atoms in straight chain. so, 3-hexanoic acid cannot exist.
f) 'but' means 4 C and cyclo means 'ring'. '5,5-dibromo' means two Br atoms are present at C5 position. But the ring has four carbons. So, the given compound is not possible.
