Diffusion and Osmosis

Materials and Procedures: For the experiment you will need the following materials: • 1 raw russet potato (large) • water (distilled preferred) • table salt (NaCl, sodium chloride) • two containers (glasses, cups, or bowls) • ***There may be additional materials that you need but are not listed. Instructions: 1) Label the first container (glass, cup, or bowl) as Variable 1 and the second container as Variable 2. ***Note: You may label a piece of paper and place it next to the container. You are not required to write on the actual container. 2) To make Solution 1 (salt water); mix approximately 3 table spoons of salt with approximately 3 cups of water. Fill the Variable 1 container with Solution 1. ***Note: The measurements and amounts don’t have to be exact, but make sure that you have enough solution to fill the container and cover the potato strip. 3) Fill the Variable 2 container with distilled water only. ***Note: Tap water or bottled water will work if you don’t have distilled water. 4) Cut one large russet potato, lengthwise, in half. From the inside of each half, cut two strips (rectangles) of potato, each about 7 cm long and 1.5 cm wide. Place one potato strip in the Variable 1 container and the other potato strip in the Variable 2 container for approximately 3 hours. 5) After 3 hours, remove the potato strips from the containers and make your observations. Recording Results: Create a table or chart to record your observations. Observe each strip of potato for limpness (water loss) or stiffness (water gain). Also observe the texture, color, firmness, and flexibility of the potatoes. Search the internet for examples of tables and charts. You may also document your observations with pictures, which you can include in the lab report. Writing a Lab Report: After you have performed the experiment, collected your data, made observations, and analyzed your results, you will create a formal summary of the entire experiment, which is called a lab report