Water is a colorless and odorless liquid. It can exist in solid, liquid, and gas states. It boils at 100 degrees C and melts at 0 degrees C. Which option best describes this information?
The Correct Answer and Explanation is:
Correct Answer:
A. Physical properties of water
Explanation
The information provided in the statement is best described as the physical properties of water. Physical properties are characteristics of a substance that can be observed or measured without changing the substance’s chemical identity. These properties help us understand the behavior and appearance of a substance in various conditions.
In the given description, water is referred to as a colorless and odorless liquid, which are sensory characteristics and fall under physical properties. Additionally, the ability of water to exist in three states—solid (ice), liquid (water), and gas (vapor)—demonstrates its state of matter under different temperature and pressure conditions, which is another key physical property.
The melting point (0°C) and boiling point (100°C) are classic examples of measurable physical properties. They indicate the temperatures at which water changes from solid to liquid (melting) and from liquid to gas (boiling) under standard atmospheric pressure (1 atm). These values are unique and constant for pure water, making them useful for identification and classification.
None of the provided information involves any chemical change or reaction (like forming a new substance). For instance, boiling or freezing water does not change it into a different compound—it remains H₂O. This lack of change in chemical composition during these processes confirms that the properties mentioned are purely physical, not chemical.
In contrast, chemical properties involve how a substance interacts with other substances to form new materials (such as water reacting with sodium), which is not discussed here.
Therefore, since the statement talks solely about observable and measurable traits of water without altering its molecular structure, the correct classification is:
A. Physical properties of water
.