Diffusion
Which statement correctly defines diffusion?
A student writes: “Particles move from high concentration to low concentration because they want to spread out.” What is the scientific error in this statement?
Diffusion occurs faster in gases than in liquids. Which explanation is correct?
A bottle of perfume is opened in the corner of a sealed room with no fans or air currents. After several minutes, a person on the opposite side of the room can smell the perfume. Which statement best explains this observation?
In the glass tube experiment, ammonia (NH₃) and hydrogen chloride (HCl) are introduced at opposite ends. A white ring of ammonium chloride forms inside the tube. What is the Mᵣ of ammonia and the Mᵣ of hydrogen chloride?
In the NH₃/HCl glass tube experiment, the white ring of NH₄Cl forms closer to which end of the tube, and why?
A student heats a beaker of water containing a drop of food colouring. Compared to performing the same experiment at room temperature, the food colouring spreads through the hot water more quickly. Which explanation is correct?
Which of the following correctly explains why diffusion does not occur in solids?
Two sealed containers at the same temperature each hold a different gas. Container X holds helium (Mᵣ = 4) and Container Y holds sulfur dioxide (Mᵣ = 64). If both containers are opened simultaneously into a large empty chamber, which gas fills the chamber first?
A student sets up the NH₃/HCl glass tube experiment but uses a different pair of gases: gas P (Mᵣ = 28) and gas Q (Mᵣ = 80). These two gases react on contact to form a visible white solid. If gas P enters from the left end and gas Q from the right end, where does the white solid form?
Which row correctly compares diffusion in gases and liquids?
An industrial chemist needs to separate two gases from a mixture as quickly as possible using a porous membrane that allows smaller, faster-moving molecules to pass through first. The mixture contains methane (CH₄, Mᵣ = 16) and carbon dioxide (CO₂, Mᵣ = 44). Which gas passes through the membrane first, and what principle explains this?