Playbook
Surface Chemistry
39 q - 0.92/paper - never HARD. Adsorption types, colloids and the Hardy–Schulze rule.
- Questions in the bank
- 39
- q/paper (2024–25 papers)
- 0.92
- Tagged HARD
- 0%
- Subtopics
- 3
Strand: Recall
When you’ll see it
Adsorption and its types, a colloid and its class, coagulation by an electrolyte, or a catalyst.
How this chapter is tested
39 q at 0.92 a paper, and never a HARD question. Colloids (21 q): lyophilic against lyophobic, the dispersed phase and medium, and the Hardy–Schulze rule — the ion with the charge OPPOSITE to the sol's coagulates it, more strongly the higher its charge.
Adsorption (12 q): physisorption (van der Waals, reversible, falls with temperature) against chemisorption (chemical bonds, specific), and the Freundlich isotherm.
The sub-skills
The distinct skills inside the chapter, in the order to learn them.
Hardy–Schulze
For a negative sol (As₂S₃): Al³⁺ > Ba²⁺ > Na⁺. For a positive sol (Fe(OH)₃): [Fe(CN)₆]⁴⁻ > SO₄²⁻ > Cl⁻.
Adsorption types
Physisorption: weak, multilayer, reversible. Chemisorption: strong, monolayer, specific.
Colloid classes
Aerosol, gel, emulsion, foam by phase and medium.
Traps to expect
Distractor shapes this chapter reuses. The Traps page covers the patterns that cut across chapters.
The ion's sign
The coagulating ion carries the charge opposite to the sol. A large anion does nothing to a negative sol.
Physisorption and heat
Physisorption decreases as temperature rises; chemisorption first increases.
Learn it before you drill it
This chapter has full teaching notes — foundations, worked examples, self-checks and a per-subtopic mastery checkpoint. Read the notes once, then drill subtopic by subtopic below.
Surface Chemistry notesDrill every surface chemistry question
39 questions from the bank, scoped to 3 bundled subtopics.
Drill one subtopic at a time
The 3 subtopics this playbook covers, in catalog order.
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