Which process is demonstrated when hydrogen gas is purified by passing it through a palladium barrier?

• A. Electrolysis
• B. Sublimation
• C. Distillation
• D. Effusion

Answer: (D)

Verified step by step guidance

1. Understand the definitions of the processes listed: Electrolysis is the decomposition of a compound using electricity; Sublimation is the transition of a substance from solid to gas without passing through the liquid phase; Distillation is the separation of components based on differences in boiling points; Effusion is the process by which gas particles pass through a tiny hole or barrier without collisions between particles.
2. Recognize that purifying hydrogen gas by passing it through a palladium barrier involves the gas passing through a selective membrane that allows only hydrogen atoms or molecules to pass through.
3. Note that this selective passage through a barrier without phase change or boiling corresponds to the concept of effusion, where gas particles move through small pores or holes.
4. Confirm that the process does not involve electrical decomposition (electrolysis), phase change from solid to gas (sublimation), or boiling and condensation (distillation).
5. Conclude that the process demonstrated when hydrogen gas is purified by passing it through a palladium barrier is effusion.