Question

Which statement is correct?1. Only nonpolar molecules have dispersion forces.2. Only molecules that can hydrogen bond have dispersion forces.3. Only polar molecules have dispersion forces.4. Evaporation is an endothermic process.5. Only molecules that cannot hydrogen bond have dispersion forces.6. None of these statements are correct.

Answer 1

Answer: Option (4) is the correct answer.

Explanation:

Evaporation is defined as a process in which molecules of a substance absorb energy and hence, they gain kinetic energy. As a result, state of the substance changes from liquid phase to vapor phase.

For example, when we boil water then heat is absorbed by molecules of the liquid and hence, they change into vapor state.

Endothermic processes are defined as the process in which heat energy is absorbed by the reactant molecules.

The weak intermolecular forces which can arise either between nucleus and electrons or between electron-electron are known as dispersion forces. These forces are also known as London dispersion forces and these are temporary in nature.

Dispersion forces are present in between both polar and non-polar molecules.

Therefore, we can conclude that evaporation is an endothermic process is the correct statement.