What type of reaction takes place when potassium iodide reacts with chlorine gas? a
Double Replacement
b
Decomposition
c
Synthesis
d
Single Replacement

The correct answer is - d. single replacement or displacement.

Explanation:

The displacement or replacement reaction is the reaction in which the less reactive molecule or element is replaced by the more reactive element or molecule in the reaction. If there is only one replacement occurs its termed as a replacement or single replacement reaction.

In this case, if chlorine gas passes through the water solution of KI (potassium iodide), solid iodine and KCl are produced by the displacement or replacement reaction. Here iodine is less reactive so replaced by the more reactive chlorine.

                                 2KI(aq)+Cl2 (g)→2KCl(aq)+I2 (s)

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.