Question

When a liquid boils, there is-
A.An increase in entropy
B.A decrease in entropy
C.An increase in heat of vaporization
D.An increase in free energy

Answer 1

We need to understand the concept of boiling and the changes that take place when a liquid is boiled. The thermodynamic aspects need to be analysed. When a liquid is heated to its boiling point, it transforms into a vapour, which is known as boiling. When the vapour pressure of a liquid equals the atmospheric pressure, the liquid transitions from a liquid to a gaseous phase. Boiling is a physical transformation in which molecules are not chemically changed.

Complete answer:
Bubbles develop and boiling happens when atoms or molecules of a liquid spread out sufficiently to transition from a liquid phase to a gaseous phase. When boiling happens, the more energetic molecules become gases, spread out, and create bubbles. These ascend to the surface and are carried into the atmosphere. It takes energy to convert a liquid to a gas. Entropy rises as a result of this. Entropy is a state function that is frequently incorrectly referred to as a system's "state of disorder." Entropy is essentially a measure of how much the energy of atoms and molecules spreads out in a process, and it may be described in terms of a system's statistical probability or in terms of the other thermodynamic variables. As a molecule changes state, the general states of matter in terms of entropy can be arranged as follows: gases > liquids > solids. As a result, when a liquid is boiled, entropy increases.

Hence, the correct option is option (A).

Note:
Note that Entropy increases due to two factors: A solid dissolves in watery media and one molecule is broken down into three ions. All of these variables raise the solute's entropy. Keep in mind that there is an entropy loss associated with the water molecules assembling their "solvent cages" around the ions. This component can occasionally result in just a minor rise in entropy, despite the fact that a significant increase is predicted. As a result, in the extremely typical scenario when a little amount of solid or liquid dissolves in a considerably greater volume of solvent, the solute spreads out in space, and the number of equivalent ways in which the solute may be dispersed within this volume is substantially enhanced. This is equivalent to saying that the solute's entropy increases.