Concept Explanation: Energy of Particles in Steam vs. Water at 373 K

At 373 K (100°C), water and steam coexist at equilibrium. This is the boiling point of water. The key concept here involves understanding the difference in energy between the liquid and gas phases at the same temperature.

Step 1: Understand Temperature and Kinetic Energy

Temperature is a measure of the average kinetic energy of particles. Since both water and steam are at 373 K, the average kinetic energy of the particles (molecules) is the same. Kinetic energy is given by:

$\mathrm{KE}=\frac{3}{2}kT$

where $k$ is Boltzmann's constant and $T$ is temperature. So, at same T, average KE is equal.

Step 2: Consider Potential Energy

However, total energy includes both kinetic and potential energy. In steam (gas phase), the molecules are far apart with weak intermolecular forces, so they have higher potential energy compared to water (liquid phase), where molecules are closer and have stronger bonds.

Step 3: Compare Total Energy

Since kinetic energy is the same but potential energy is higher in steam, the total energy of particles in steam is greater than that in water at the same temperature.

Final Answer

Therefore, the energy of particles in steam at 373 K is greater than the energy of particles in water at 373 K.

So, the correct option is: > Energy of particles in water at 373K.

Related Topics

• Phase Transitions (e.g., boiling, condensation)
• Intermolecular Forces
• Latent Heat (specifically latent heat of vaporization)
• Thermodynamics and Energy Distribution

Key Formulae and Theory

Average Kinetic Energy per molecule: $\mathrm{KE}=\frac{3}{2}kT$

Latent Heat of Vaporization (L_v): The energy required to convert a unit mass of liquid into vapor at constant temperature. It is the energy that increases the potential energy of the molecules without changing the kinetic energy (hence temperature remains constant during phase change).

Intermolecular Potential Energy: In gases, it is nearly zero; in liquids, it is negative (due to attractive forces). So, to go from liquid to gas, work is done against these forces, increasing potential energy.