JEE Main 2015 Chemistry question

Not in JEE Main or NEET syllabus

The following statements relate to the adsorption of gases on a solid surface. Identify the **incorrect** statement among them:

(1)Entropy of adsorption is negative
(2)Enthalpy of adsorption is negative
(3)On adsorption decrease in surface energy appears as heat
(4)On adsorption, the residual forces on the surface are increasedCorrect

Answer: (4)

Solution

Adsorption occurs precisely *because* the surface particles of a solid have unbalanced (residual) valence forces; adsorbing gas molecules satisfies these forces, so the residual forces on the surface **decrease**, not increase. Statement (4) is therefore the incorrect one. The others are all correct: adsorption

See the full step-by-step solution

Create a free account to read the complete working, and practise questions like this in a timed test.

Create a free account

Question ID VK-115271