No, water turning into ice in the freezer is not a physical property. It is best described as a physical change.
Understanding Physical Changes vs. Physical Properties
While related concepts in chemistry and physics, a physical property and a physical change are distinct.
According to the provided reference:
"When water is frozen, the ice thus form has the same chemical properties as that of water only there is a change in the state of water from liquid to solid. That is why freezing of water is a physical change." (03-Jul-2022)
This clearly states that the process of freezing water is a physical change.
Why Freezing is a Physical Change
A physical change alters the form or appearance of a substance but does not change its chemical composition. When water freezes into ice:
- It changes from a liquid state to a solid state.
- The chemical formula remains H₂O. The water molecules themselves are not broken apart or rearranged to form a new substance.
- The chemical properties (like flammability or reactivity) stay the same.
This aligns perfectly with the definition of a physical change, as highlighted by the reference.
Defining Physical Properties
A physical property, on the other hand, is a characteristic of a substance that can be observed or measured without changing the substance's chemical identity. Examples include:
- Melting point
- Boiling point
- Density
- Color
- Hardness
- State of matter (at a given temperature and pressure)
For water, its freezing point (0°C or 32°F) is a physical property. The ability to freeze is also related to its physical properties. However, the process of freezing itself is the physical change.
Defining Physical Changes
A physical change involves altering the form or appearance of a substance without changing its chemical identity. Examples include:
- Freezing (liquid to solid)
- Melting (solid to liquid)
- Boiling or evaporation (liquid to gas)
- Condensation (gas to liquid)
- Sublimation (solid to gas)
- Cutting or breaking
- Bending or shaping
- Dissolving (in many cases)
Comparing Physical Property and Physical Change
Here's a simple comparison:
Feature | Physical Property | Physical Change |
---|---|---|
What it is | A characteristic of a substance | A process that alters form/appearance |
Chemical ID | Remains unchanged | Remains unchanged |
Examples | Melting point, color, density | Freezing, melting, cutting, dissolving |
Regarding Water | Freezing point (0°C), liquid state | Turning into ice (freezing), boiling water |
In summary, while water has the physical property of a freezing point, the act of turning into ice is the physical change it undergoes at that point.