Carbon tetrachloride displays a triple point at 249.0 K and a melting point (at 1 atm) of 250.3 K. Which state of carbon tetrachloride is more dense, the solid or the liquid, and why?

Verified step by step guidance

Identify the given data: the triple point temperature is 249.0 K, and the melting point at 1 atm is 250.3 K.

Understand that the triple point is the condition under which all three phases (solid, liquid, and gas) coexist in equilibrium.

Recognize that the melting point at 1 atm is higher than the triple point temperature, indicating that the solid is more stable at lower temperatures and pressures.

Recall that if the melting point at 1 atm is higher than the triple point temperature, it suggests that the solid is denser than the liquid. This is because, at the triple point, the solid can exist at a lower pressure than the liquid, implying higher density.

Conclude that the solid state of carbon tetrachloride is more dense than the liquid state, as indicated by the relationship between the triple point and the melting point.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Triple Point

The triple point of a substance is the unique set of conditions at which all three phases (solid, liquid, and gas) coexist in thermodynamic equilibrium. For carbon tetrachloride, this occurs at 249.0 K, indicating that at this temperature and specific pressure, the solid, liquid, and vapor phases can exist simultaneously.

Density and Phase Behavior

Density is defined as mass per unit volume and varies between different states of matter. Generally, solids are denser than liquids due to closely packed particles. However, some substances, like water, exhibit the opposite behavior. Understanding the density of carbon tetrachloride in its solid and liquid states is crucial for determining which phase is denser.

Melting Point

The melting point is the temperature at which a solid becomes a liquid at a given pressure, indicating a phase transition. For carbon tetrachloride, the melting point is 250.3 K at 1 atm. Since the melting point is above the triple point, it suggests that at temperatures just above this point, carbon tetrachloride exists as a liquid, which can help in comparing the densities of the solid and liquid states.

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