Same chapter3 marksDifficulty: Medium
What is meant by the promoter and the poison of a catalyst? Give one example of each.
Surface Chemistry
3 marksDifficulty: Medium
Distinguish between physisorption and chemisorption.
Original Khojo Papers practice question — not from a past board paper.
Answer
Physisorption is caused by weak van der Waals forces, has a low enthalpy of about 20 to 40 kJ per mole, is reversible, needs no activation energy and is not specific. Chemisorption involves the formation of chemical bonds, has an enthalpy of about 80 to 240 kJ per mole, is usually irreversible, requires activation energy and is highly specific.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Physisorption decreases with temperature while chemisorption first increases and then decreases.
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