<p> SBI3C Lab: Diffusion and Osmosis</p><p>PART A: DIFFUSION</p><p>Diffusion is the movement of molecules through a selectively permeable membrane from an area of high concentration (lots of molecules) to an area of low concentration (not a lot of molecules). This is so there will be equal number of molecules on both sides of the membrane.</p><p>Selectively permeable membranes are those that have openings called pores. Pores let water, oxygen, carbon dioxide and other specific small molecules go through the membrane. </p><p>Brewing tea and making coffee involves the diffusion of tea or coffee molecules into water. </p><p>Procedure:</p><p>1. Place 200 mL of hot water, room temperature water (warm to the touch) and cold water into 3 separate beakers. </p><p>2. Gently place a tea bag on the surface of the water in each beaker at the same time. Do not disturb/move this tea bag. </p><p>3. Observe the diffusion process in each beaker and record it in the table below.</p><p>Observations:</p><p>Tea bag in HOT water Tea bag in WARM water Tea bag in COLD water</p><p>Questions:</p><p>1. Does the filter paper of the teabag act as a selectively permeable membrane? Explain. 2. How did the temperature of the water affect the diffusion of tea molecules in each of the three beakers?</p><p>PART B: OSMOSIS </p><p>Osmosis is the diffusion of water molecules across a selectively permeable membrane. This means that water can go through membranes from areas where there are a lot of water molecules to areas where there are not so many water molecules.</p><p>Observations:</p><p>Day 1 – Raw Egg</p><p>Day 2 – Egg soaked in vinegar Draw a diagram of the egg in the beaker. Use arrows to show the movement of particles.</p><p>Day 3 – Egg soaked in corn syrup Draw a diagram of the egg in the beaker. Use arrows to show the movement of particles.</p><p>Day 4 – Egg soaked in water Draw a diagram of the egg in the beaker. Use arrows to show the movement of particles. Questions:</p><p>1. When the egg was placed in the water, which direction did the water molecules move? Explain your answer.</p><p>2. Why do grocery stores spray their fresh produce with water?</p><p>3. If a shipwrecked crew drank salt water, they could die. Explain why.</p><p>4. If you sprinkle a vegetable such as zucchini or eggplant with salt, a few minutes later, they will be covered with juice. Explain why this happens. </p>