Answer the question on the basis of the passage given below:

Adsorption is a surface phenomenon and it differs from absorption which occurs throughout the body of the substance which absorbs. In physisorption, the attractive forces are mainly van der Waal forces while in chemisorption actual bonding occurs between the particles of adsorbent and adsorbed more easily on the surface of a solid as compared to the gases which are liquified with difficulty. Adsorption increases with increase in pressure and decreases as the temperature is increased.

The effect of pressure on adsorption is high if

temperature is low

The correct answer is option 1. temperature is low.

The effect of pressure on adsorption is influenced by factors such as temperature and the nature of the adsorbent and adsorbate. Let's explore the relationship between pressure and adsorption in more detail, focusing on the impact of temperature:

1. Low Temperature:

At low temperatures, gas molecules possess lower kinetic energy. With reduced kinetic energy, gas molecules are less likely to overcome the potential energy barrier and escape from the gas phase to be adsorbed onto the surface of the adsorbent. The lower temperature allows for a higher degree of interaction between gas molecules and the adsorbent surface, leading to increased adsorption.

2. High Temperature:

Conversely, at high temperatures, gas molecules have higher kinetic energy. Higher kinetic energy enables gas molecules to overcome potential energy barriers more easily and escape from the gas phase, reducing the likelihood of adsorption. The increased thermal motion at higher temperatures can weaken the attractive forces between the adsorbate molecules and the adsorbent surface.

3. Temperature and Adsorption Isotherms:

Adsorption is often described by adsorption isotherms, which represent the relationship between the amount of adsorbate adsorbed and the pressure (or concentration) at constant temperature. Common adsorption isotherms include the Langmuir and Freundlich isotherms, which provide insights into the adsorption behavior of a system.

4. Effect of Pressure:

In general, higher pressures can enhance adsorption because increased pressure results in a higher concentration of gas molecules, leading to a greater chance of interaction with the adsorbent surface. However, the impact of pressure on adsorption can be more pronounced at lower temperatures due to the factors mentioned earlier.

In summary, the effect of pressure on adsorption is higher at low temperatures. Lower temperatures generally favor adsorption by reducing the kinetic energy of gas molecules and allowing for stronger interactions between the adsorbent surface and the adsorbate. This relationship is often observed in gas adsorption processes, and understanding these factors is crucial for optimizing adsorption conditions in various applications, such as gas separation and purification processes.