Part 1A: Designing the Experiment olecules of any substance move through the med
ID: 1074235 • Letter: P
Question
Part 1A: Designing the Experiment olecules of any substance move through the medium they are in. In diffu- sion, molecules move from their higher concentration to the lower concentra- tion. The rate of diffusion is affected by various parameters such as physical state of the medium, temperature and molecular weight of the substance. The medium in which diffusion occurs can be in three different physical states: solid, liquid or gas. As you may already know, different physical mediums have different arrangement of atoms and molecules. Solid medium is the most organized and gas is the least organized with liquid state being in-between. We will study whether or not the physical state of the medium (solid and liquid) has any effect on the movement of substances. We will compare move- ment of a colored substance in solid medium (agar plate) and liquid medium (water). In Part 1A, you will first apply scientific method, design experiment and predict outcomes. In Part 1B, you will actually do the experiment, collect data and derive conclusions to see if your hypothesis can be accepted/revised or rejected. The Materials Given to You are: 1. Mediums in two different physical states a. Liquid: DI Water (use tap water) b. Solid: Agar plate 2. Substance: Congo red 3. Ruler for measurement 4. Empty petri plate 5. Measuring CylinderExplanation / Answer
5. The results you are expected to see: The congo red molecules move from Agar plate to water.
Explanation: Agar plate is solid with high concentration and water is liquid. According to the principle of diffusion, the molecules move from their high concentration to low concentration.
6. The most likely conclusions of the study based on the predicted result: The movement of the molecules of congo red is slower in agar plate than that in water. As a result, the molecules move to water from agar plate.
Explanation: The liquid is more disordered than the solid. Hence, the movement of molecules is faster in more disordered medium, i.e. water. Hence, the congo red molecules move from their high concentration (in solid, i.e. agar plate) to low concentration (in liquid, i.e. water).