Naphthalene balls disappear with time without leaving any solid because of sublimation are naphthalene balls disappear with time without leaving any Residue because because nothing ball go under sublimation

Introduction:

Naphthalene balls, also known as mothballs, are widely used as a household insect repellent and for preserving clothes and other items. These small white balls contain naphthalene, a solid aromatic hydrocarbon, which evaporates slowly over time. It is common to notice that naphthalene balls gradually disappear without leaving any solid residue behind. This phenomenon can be explained by the sublimation process and the volatile nature of naphthalene.

Sublimation Process:

Naphthalene undergoes sublimation, which is the process of transitioning directly from a solid to a gas phase without passing through the liquid phase. This occurs because the vapor pressure of naphthalene exceeds its melting point, causing it to evaporate at room temperature. Sublimation is a common behavior of certain substances, such as dry ice (solid carbon dioxide) and camphor.

Volatile Nature of Naphthalene:

Naphthalene is highly volatile, meaning it easily converts from a solid to a gas phase. This volatility is due to the weak intermolecular forces between naphthalene molecules. The van der Waals forces holding the naphthalene molecules together are relatively weak, allowing them to break apart and escape into the air as gas molecules.

Evaporation and Dispersion:

When naphthalene balls are exposed to the surrounding air, the naphthalene molecules on the surface start to evaporate. These gaseous molecules disperse into the air, creating a concentration gradient. As a result, more naphthalene molecules from the interior of the ball move towards the surface, replenishing the evaporating molecules. This continuous process eventually leads to the gradual disappearance of the naphthalene balls.

No Solid Residue:

Since naphthalene undergoes sublimation and converts directly from a solid to a gas phase, it does not leave any solid residue behind. Unlike substances that undergo combustion or decomposition, naphthalene does not produce solid byproducts. The naphthalene molecules simply disperse into the air, leaving no visible trace.

Conclusion:

The disappearance of naphthalene balls without leaving any solid residue is primarily due to the sublimation process and the volatile nature of naphthalene. As naphthalene evaporates from the surface of the balls, the molecules disperse into the air, gradually depleting the solid material. This phenomenon is a result of the weak intermolecular forces in naphthalene and its ability to transition directly from a solid to a gas phase.