Question

Are single displacement reactions exothermic?

Answer 1

At a given temperature and chemical concentration, chemical reactions occur at a predictable pace. Reaction speeds often increase as temperature rises because more thermal energy is available to attain the activation energy required to break bonds between atoms. Reactions can move in either a forward or backward direction until they finish or achieve equilibrium. The term "spontaneous" refers to reactions that proceed in the forward direction to reach equilibrium without requiring any free energy input.

Complete answer:
At a given temperature and chemical concentration, chemical reactions occur at a predictable pace. Reaction speeds often increase as temperature rises because more thermal energy is available to attain the activation energy required to break bonds between atoms. Reactions can move in either a forward or backward direction until they finish or achieve equilibrium. The term "spontaneous" refers to reactions that proceed in the forward direction to reach equilibrium without requiring any free energy input.
Exothermic process (exo- : "outside") is a word used in thermodynamics to describe a process or reaction that transfers energy from a system to its surroundings, most commonly in the form of heat, but also in the form of light (e.g. a spark, flame, or flash), electricity (e.g. a battery), or sound (e.g. explosion heard when burning hydrogen).
A single-displacement reaction is a chemical reaction that occurs when one element in a molecule is replaced by another.
It can be expressed in the following way:
$A+BC\to AC+B$
Energy is either released or absorbed during a chemical process. The reaction is exothermic if energy is released. The creation of bonds is an exothermic reaction. Because the atoms are moving to a lower energy state, energy is released. It takes energy to break a connection, according to the same logic (endothermic).
We must break the B-C bond and form an A-C bond in the reaction $A\text{ }+\text{ }B-C\text{ }\to \text{ }B\text{ }+\text{ }A-C$. There will be a net release of energy if the creation of the A-C bond releases more energy than the energy required to break the B-C bond. It will be an exothermic reaction. The reaction will not occur spontaneously if the process is endothermic since the system is already in a more stable state.
Hence they are exothermic.

Note:
The heat emitted by exothermic chemical processes is in the form of electromagnetic energy or the kinetic energy of molecules. Light is emitted as electrons shift from one quantum energy level to another. This light has the same energy as the energy for the chemical reaction's stabilisation energy. This light may be absorbed by other molecules in solution, causing molecular translations and rotations, which is how heat is understood in the traditional sense. In an exothermic reaction, the energy required to initiate the reaction is less than the energy released afterwards, resulting in a net energy release.