Example of vinylic halide is :

Solution

Chemistry ma’am · 3 steps

Find the carbon that holds X: if that carbon is part of the C=C itself, the halide is vinylic.

1. Three labels. Vinylic: X sits on an sp² carbon of a C=C. Allylic: X sits on an sp³ carbon right next to a C=C. Aryl: X sits on a benzene ring carbon.
2. How to check. Do not stop once you see a double bond somewhere in the molecule. Look only at the carbon bonded to X and ask whether that carbon is one end of the C=C.

   Option	Carbon holding X	Type
   (a) X on cyclohexene ring	sp³ ring carbon next to the C=C	allylic
   (b) CH₂X on cyclohexene	sp³ CH₂ carbon next to the C=C	allylic
   (c) X on benzene	sp² carbon of an aromatic ring	aryl
   (d) XCH= on cyclohexane	sp² carbon of the exocyclic C=C	vinylic

3. So. Only in (d) is X bonded directly to a carbon of the C=C double bond, so (d) is the vinylic halide.

The idea to keep. Vinylic means X on a double-bond carbon. Allylic means X one carbon away from it. Aryl means X on a benzene ring. Always check the carbon that carries X.

Answer from the NTA final answer key. Solution by PrepWiser.