The rate of solvolysis of I–IV follows 
The problem involves determining the rate of solvolysis of the given compounds (I–IV). Solvolysis is a type of nucleophilic substitution where the solvent acts as the nucleophile. The rate of solvolysis is influenced by the stability of the carbocation formed during the reaction. More stable carbocations lead to faster solvolysis rates.
Let's analyze each compound:
Therefore, the order of solvolysis rate from fastest to slowest is:
III > II > I > IV