Triple Point in p-T Diagram

The triple point is a unique point in a substance's phase diagram at which the three phases (solid, liquid, and gas) coexist in equilibrium. The triple point can be represented on various types of phase diagrams, such as p-V, p-T, h-S, and T-s diagrams. However, the correct option for the triple point representation is the p-T diagram.

Explanation:

- A phase diagram is a graphical representation of the conditions of temperature and pressure under which a substance exists in different phases.
- The p-T diagram is a type of phase diagram that shows the relationship between pressure and temperature at which a substance exists in different phases. It is a two-dimensional graph with pressure on the y-axis and temperature on the x-axis.
- The triple point is the point on the p-T diagram where the solid, liquid, and gas phases of a substance coexist in equilibrium at a specific pressure and temperature.
- At the triple point, the three phases of the substance have the same pressure, temperature, and chemical potential, which means that they can coexist in equilibrium without any phase change.
- The triple point is a critical point in a substance's phase diagram because it represents the minimum pressure and temperature at which the substance can exist in all three phases simultaneously.
- The triple point is also used to define the standard pressure and temperature (STP) conditions, which are 1 atm and 273.15 K, respectively.

Conclusion:

In conclusion, the correct option for the triple point representation is the p-T diagram. The triple point is a unique point in a substance's phase diagram where the solid, liquid, and gas phases coexist in equilibrium at a specific pressure and temperature. The p-T diagram is a two-dimensional graph that shows the relationship between pressure and temperature at which a substance exists in different phases.