Identify [A], [B], and [C], respectively in the following reaction sequence : 





To identify the compounds [A], [B], and [C] in the given reaction sequence, let's analyze each step of the reaction.
Step 1: The first reaction involves the treatment of [A] with \(\text{NaNO}_2\) and \(\text{HCl}\) at 273–278 K.
This is a typical diazotization reaction where an aromatic amine (aniline) is converted into a diazonium salt. Thus, [A] is aniline, \(\text{C}_6\text{H}_5\text{NH}_2\).
Step 2: The diazonium salt formed reacts with KI.
This is a Sandmeyer reaction where the diazonium group is replaced by iodide to form an iodobenzene compound. Hence, [B] is iodobenzene, \(\text{C}_6\text{H}_5\text{I}\).
Step 3: The compound undergoes a reaction with 2Na in dry ether.
This reaction is a typical Wurtz reaction where iodobenzene reacts with sodium to form biphenyl. Therefore, [C] is biphenyl, \(\text{C}_6\text{H}_5\text{-C}_6\text{H}_5\).
The complete reaction sequence can be summarized as follows:
From the given options, the correct identification of [A], [B], and [C] is as follows:
Thus, the correct answer is: Aniline ([A]) → Iodobenzene ([B]) → Biphenyl ([C]).
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are


What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)