Surface Chemistry

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Adsorption: Surface phenomenon where molecules accumulate on the surface of a solid (adsorbent). Example: Charcoal adsorbing ammonia gas. Absorption: Bulk phenomenon where molecules penetrate through…

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Adsorbent: The material on which adsorption takes place (e.g., charcoal, silica gel, metals like Ni, Cu, Pt). Adsorbate: The substance being adsorbed (e.g., gases like NH₃, CO₂, SO₂, or solutions lik…

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According to the Gibbs free energy equation: ΔG = ΔH - TΔS For adsorption to be spontaneous, ΔG must be negative. During adsorption: - ΔS is negative (decrease in randomness as molecules are confined…

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Physical Adsorption: - Forces: van der Waals forces, dipole-dipole interactions - Heat of adsorption: ~4-40 kJ/mol (low) - Layer formation: Multilayer - Temperature effect: Decreases with increase in …

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1. Surface Area: Higher surface area → greater adsorption (adsorption is surface phenomenon) 2. Nature of Adsorbate: Gases with high critical temperature (easily liquefiable like SO₂, NH₃) are adsorb…

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Freundlich Adsorption Isotherm: x/m = Kp^(1/n) Where: - x = amount of adsorbate adsorbed - m = mass of adsorbent - p = pressure of gas (or c for concentration in solutions) - K = Freundlich constant …

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Given: - K = 2.5 - p = 5 atm - n = 3 - m = 10 g Using Freundlich equation: x/m = Kp^(1/n) Step 1: Calculate 1/n = 1/3 = 0.333 Step 2: Calculate p^(1/n) = 5^(0.333) = 5^(1/3) = 1.71 Step 3: x/m = 2…

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Definition: A catalyst is a substance that alters the rate of a chemical reaction without itself undergoing any permanent chemical change. Key Characteristics: 1. Required in small quantities (a pinc…