Distinguish between the given pairs.
`a.`
`b.`
`c.`
`d.`

Explanation

a. Compounds `(A)` and `(B)` are distinguished chemically by quantitative catalytic hydrogenation. Compound `(A)` will require `2 mil` of `H_(2)`, for ` 1 mol` of `(A)` while `(B)` will require `1 mil` of `H_(2)` per mole of `(B)` .
b.
Allene (C) with different groups on each of the double bonds is opticaly active and can be resolved into its enantiomers.
Compound (D) is a conjugated diene adn does not show optical isomerism.
c. (E) is an `S-cis ` conjugated diene and undergoes a Diels `-` Alder reaction when heated with a dienophile, such as maleic anhydride, to give a new solid product that is determined by its melting point.

(3- Methylene cyclohex -1- ene)(F) has a rigid S-trans arrangement and does not undergo Diels `-` Alder reaction.
d. Diene `(G)` with Baeyer's reagent (cold alkaline `KMnO_(4))` decolourises the pink (or purple) colour of `KMnO_(4) ` and diene is oxidised with `KMnO_(4)` to give a brown `-` black precipitate of `MnO_(2)`.