Statement: Physical adsorption is weaker than chemical adsorption.
Explanation: Activated complex formed during adsorption possess lower energy level in chemisorption as it is more exothermic.
Statement: Physical adsorption is weaker than chemical adsorption.
Explanation: Activated complex formed during adsorption possess lower energy level in chemisorption as it is more exothermic.
The correct option is C Both statement and explanation are correct and explanation is correct explanation of statement
Adsorption is the phenomenon of accumulation of large number of molecular species at the surface of liquid or solid phase in comparison to the bulk.
It is of following two types:
1. Physical Adsorption (Physisorption)
2. Chemical Adsorption (Chemisorption)
Adsorption processes take place by adsorbate getting adsorbed on adsorbent. Forces of attraction exist between adsorbate and adsorbent and due to these forces of attraction, heat energy is released. So, all adsorptions are exothermic processes.
1. Physical Adsorption: When the force of attraction existing between adsorbate and adsorbent are weak van der Waal forces of attraction, the process is called Physical adsorption or Physisorption. Physical adsorption takes place with formation of multilayer of adsorbate on adsorbent. It has low enthalpy of adsorption, i.e., ΔHadsorption is 20−40 kJ/mol.It takes place at low temperature below boiling point of adsorbate.As the temperature increases in, process of Physisorption decreases.
2.Chemical Adsorption: When the force of attraction existing between adsorbate and adsorbent are chemical forces of attraction or chemical bond, the process is called Chemical Adsorption or Chemisorption. Chemisorption takes place with formation of unilayer of adsorbate on adsorbent. It has high enthalpy of adsorption, i.e., ΔHadsorption is 200−400 kJ/mol. It can take place at all temperature. With the increases in temperature, Chemisorption first increases and then decreases.
Hence, the answer is Option C.
Adsorption is the phenomenon of accumulation of large number of molecular species at the surface of liquid or solid phase in comparison to the bulk.
It is of following two types:
1. Physical Adsorption (Physisorption)
2. Chemical Adsorption (Chemisorption)
Adsorption processes take place by adsorbate getting adsorbed on adsorbent. Forces of attraction exist between adsorbate and adsorbent and due to these forces of attraction, heat energy is released. So, all adsorptions are exothermic processes.
1. Physical Adsorption: When the force of attraction existing between adsorbate and adsorbent are weak van der Waal forces of attraction, the process is called Physical adsorption or Physisorption. Physical adsorption takes place with formation of multilayer of adsorbate on adsorbent. It has low enthalpy of adsorption, i.e., ΔHadsorption is 20−40 kJ/mol.
It takes place at low temperature below boiling point of adsorbate.As the temperature increases in, process of Physisorption decreases.
2.Chemical Adsorption: When the force of attraction existing between adsorbate and adsorbent are chemical forces of attraction or chemical bond, the process is called Chemical Adsorption or Chemisorption. Chemisorption takes place with formation of unilayer of adsorbate on adsorbent. It has high enthalpy of adsorption, i.e., ΔHadsorption is 200−400 kJ/mol. It can take place at all temperature. With the increases in temperature, Chemisorption first increases and then decreases.
Hence, the answer is Option C.
