Question

The phase diagram of water is best represented by

• A.
• B.

  

• C.

  

• D.

  

Answer 1

The Correct Option is D

The phase diagram of water is an important topic in physical chemistry as it provides insight into the states of water under various temperature and pressure conditions. A phase diagram illustrates the conditions of temperature and pressure at which distinct phases occur and coexist at equilibrium.

In the context of the question, we are asked to identify the correct phase diagram of water from given options. The correct answer is usually characterized by a few distinctive features specific to water:

• Water's solid-liquid boundary line (line between solid and liquid phases) has a negative slope, unlike most other substances. This indicates the unusual behavior of water where ice melts under increased pressure.
• There is a triple point where all three phases (solid, liquid, and gas) coexist in equilibrium.
• The critical point marks the end of the liquid-gas boundary line and indicates the conditions above which distinct liquid and gas phases do not exist.

The correct phase diagram for water will accurately represent these features. Here is the phase diagram identified as correct from the options provided:

This diagram shows the negative slope of the solid-liquid boundary and the coexistence of the three phases at the triple point, which are typical characteristics of water's phase diagram.

Understanding the phase diagram of water is crucial because it explains various anomalous properties of water, such as why ice floats on liquid water and how it behaves under high pressure.