Question

For the reaction $2C{l_{\left( g \right)}} \to C{l_2}$ . What are the signs of $\Delta H$ and $\Delta S$ ?

Answer 1

A molecule is a chemically bound collection of two or more atoms that are electrically neutral. Molecules differ from ions in that they do not have an electrical charge. In quantum physics, organic chemistry, and biochemistry, the difference between ions and molecules is typically omitted, and polyatomic ions are referred to as molecules. The term molecule is frequently used in the kinetic theory of gases to refer to any gaseous particle, regardless of composition. Because noble gases are single atoms, this defies the concept of a molecule, which states that it must include two or more atoms.

Complete answer:
Entropy is a measure of a system's unpredictability or disorder in general. Aside from the basic description, there are a number of other meanings available for this subject. The thermodynamic definition and the statistical definition of entropy are the two definitions we'll look at here. We don't examine the tiny features of a system while looking at entropy from a thermodynamics standpoint. Entropy, on the other hand, is used to explain a system's behaviour in terms of thermodynamic characteristics like temperature, pressure, entropy, and heat capacity. The condition of equilibrium of the systems was taken into account in this thermodynamic description.
The measurement of energy in a thermodynamic system is enthalpy. The entire content of heat in a system is enthalpy, which is equal to the system's internal energy plus the product of volume and pressure. Enthalpy is a technical term that defines the amount of internal energy necessary to create a system as well as the amount of energy required to make place for it by establishing its pressure and volume and displacing its surroundings. The developed heat (either absorbed or emitted) equals the change in enthalpy when a process starts at constant pressure.
Here in $2C{l_{\left( g \right)}} \to C{l_2}$
The atoms in a molecule form a molecule, which makes the system less chaotic. The reaction's entropy is lowering $\Delta S$ (negative). Furthermore, because the addition process is exothermic because a bond is created, $\Delta H$ is also negative.

Note:
Internal energy is the total amount of energy stored in the gadget. It is the quantity of potential and kinetic energy retained by the mechanism. The quantity of internal energy plus the combination of the system's gas pressure and length is referred to as enthalpy. Heat absorption is an endothermic process. It will have a positive enthalpy, and its surroundings will cool down. This is an exothermic process (negative enthalpy, heat release). When the reaction occurs, the temperature of the atmosphere may rise due to the increase in heat emitted by the device.