Why does the temperature drop after the stoichiometric point?

The temperature drop after the stoichiometric point/ equivalence point.

Reason:

Actually at the equivalence point, the titrant and analytes have completely reacted, that's why temperature drop.

Note: The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of bases and acids have been mixed

a electronegativity decreases beacuse the size of nucleus is bigger.