
The reactivity of halides towards the S$_N$1 mechanism depends on the stability of the carbocation intermediate formed during the reaction:
Compound A forms a benzyl carbocation, which is highly stable due to resonance.
Compound B forms a primary carbocation, which is less stable but reacts due to iodine's leaving group strength.
Compound C forms a tertiary carbocation, which is very stable and reactive.
Compound D forms a primary carbocation, less stable but reacts due to bromine's moderate leaving group strength.
Thus, the halogens are ordered as per the leaving group stability in S$_N$1.
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 : \(A_2 \rightleftharpoons 2A\)