Question 35

This is an example of water's characteristic as a good solvent.

When a pinch of salt is added to water and becomes invisible, it demonstrates water's ability to dissolve substances, which is a key characteristic of being a good solvent.

A) Temperature stability

Temperature stability refers to water's ability to resist changes in temperature. While this is an important property of water, it does not relate to the dissolution of salt, as the process of salt disappearing does not involve temperature fluctuations.

B) Good solvent

Water is known as the universal solvent due to its polarity, which allows it to dissolve a wide range of substances, including salts. The fact that the salt is no longer visible after being added to water exemplifies this property, confirming that water effectively dissolves the salt.

C) Cohesion

Cohesion describes the attraction between water molecules, which allows them to stick together. Although this property is crucial for various water behaviors, it does not apply to the interaction between water and salt, hence it is not the correct answer in this context.

D) Density

Density pertains to the mass of a substance relative to its volume. While water's density plays a role in various physical processes, it does not explain why salt becomes invisible after being added to water. Therefore, it is not relevant to the question.

Conclusion

The correct answer, "good solvent," highlights water's unique ability to dissolve substances like salt, making it an essential characteristic of this liquid. In contrast, the other options focus on different properties of water that do not pertain to the phenomenon of salt dissolving, thus reinforcing why they are incorrect in this context.