The structure of the reactive intermediate generated by reaction of CHCl₃ and KOH is

Concept:

• Carbenes are neutral species with two unshared valence electrons, that is, these species are electron deficient species.
• Parent carbene, CH₂, is also called methylene. These are short lived species.
• Carbenes are of two types( classified on the basis of spin multiplicity): 1. singlet carbenes and 2. triplet carbenes
• Singlet carbenes or fisher carbenes have their spin paired electrons. They are sp² hybridised and acts as an electrophile
• Triplet carbenes or schrock carbene have unpaired valence electrons and they are either sp² or sp hybridised. They acts as nucleophile.

Explanation:

The reaction of CHCl₃ with KOH gives carbene intermediate:

The resultant carbene is singlet because lone pair of Cl can be back donate in the empty p-orbital to stabilize it.The spin paired valence electrons stays in hybrid sp² orbital.

Structure of generated singlet carbene is: 

Conclusion:

Hence, CHCl₃ on reaction with KOH generates a singlet carbene, (:CCl₂ ) whose structure is: