Understanding Water Freezing and Expansion in a Glass Vessel

Let's analyze what happens when a glass vessel filled with water to the rim is sealed and placed in a freezer. This scenario involves a fundamental property of water when it transitions from a liquid state to a solid state (ice).

Water's Unique Expansion Property

Most substances contract when they freeze, meaning their solid form is denser than their liquid form. However, water is unusual. When water freezes, its volume increases by about 9%. This phenomenon is known as anomalous expansion.

This expansion occurs because water molecules form a crystalline structure in ice that is less dense than the liquid structure. Think of it like rearranging items: sometimes they take up more space when neatly arranged than when they are jumbled together.

Mathematically, the density of ice is approximately $0.92 \, \text{g/cm}^3$, while the density of liquid water at its maximum density (around $4^\circ \text{C}$) is $1.00 \, \text{g/cm}^3$. Since density is mass divided by volume ($\rho = \frac{m}{V}$), for a given mass, if density decreases, volume must increase.

Analyzing the Scenario: Water in a Sealed Glass Vessel

In this situation, the glass vessel is filled to the brim, and a lid is fixed tightly. This means there is no significant empty space (like air) above the water level to accommodate any change in volume. When the vessel is placed in a freezer, the temperature drops, causing the water to cool and eventually freeze.

As the water begins to freeze into ice, it attempts to expand. Since the vessel is completely full and tightly sealed, the expanding ice has nowhere to go. It exerts tremendous pressure outwards on the walls of the glass vessel and upwards/downwards on the lid/base.

Glass, while rigid, has a limit to how much pressure it can withstand. The pressure exerted by the expanding ice is often greater than the tensile strength of the glass.

Evaluating the Options

• The water freezes to ice and the level of ice comes down: This is incorrect. Water expands when it freezes, so the volume and 'level' (if unrestrained) would go up, not down.
• The water in the glass vessel simply freezes to ice: This is partially correct in that it freezes, but it misses the critical consequence of the expansion in a constrained space.
• The glass vessel breaks due to expansion as water freezes to ice: This accurately describes the expected outcome. The expansion of water into ice creates pressure that exceeds the strength of the glass vessel.
• The water does not freeze at all: This is incorrect. A freezer's purpose is to lower temperature below the freezing point of water, typically $0^\circ \text{C}$ ($32^\circ \text{F}$). Water will freeze under these conditions.

Therefore, the most likely outcome, given the expansion of water upon freezing and the rigid, sealed nature of the glass vessel, is that the vessel will break.

Revision Table: Water Freezing Properties

Additional Information: Anomalous Expansion of Water

The anomalous expansion of water is crucial for life on Earth. Consider a lake freezing. Ice forms on the surface because it is less dense than liquid water and floats. This layer of ice insulates the water below, preventing the entire lake from freezing solid, which allows aquatic life to survive through the winter.

The expansion force is quite significant. It's why water pipes can burst in freezing temperatures if the water inside freezes. It's also used in processes like frost weathering, where water seeps into cracks in rocks and expands upon freezing, gradually breaking the rock apart.

Understanding this property helps explain various natural phenomena and engineering challenges related to freezing temperatures.