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Diffusion Lab Assignment

Go to your student portal in eScience and click the “Diffusion” lab. Complete the following assignment:

Pre-Lab Questions. Answer the following questions in complete sentences after reading through “Diffusion” information

1. A concentration gradient affects the direction that solutes diffuse. Describe how a molecules move with respect to the concentration.

2. How does the size of a solute affect the rate of diffusion? Consider the size and shape of a molecule in your response.

3. Does polarity affect the rate of diffusion? Explain your answer.

Experiment 1: Diffusion through a Liquid

In this experiment, you will observe the effect that different molecular weights have on the ability of dye to travel through a viscous medium.

Materials: 

* (1) 60mL Corn Syrup Bottle

* Red and Blue Dye Solutions (blue molecular weight = 793g/mole; Red molecular weight = 496g/mole)

* (1) 9cm Petri Dish (top & bottom halves)

* Ruler

* *Stop watch

* *Tape

*You Must Provide

Insert a picture of your collected lab material here. Do not submit it separately. Insert it into this document. If you do not submit a picture, you will NOT receive credit for this lab. You will receive a zero for this assignment.

<insert picture here>

Procedure:

1. Use clear tape to secure one half (either the bottom or the top half is fine) of the petri dish over a ruler. Make sure you can read the measurement markings on the ruler through the petri dish. The dish should be positioned with the open end of the dish facing upwards.

2. Carefully fill the half of the petri dish with corn syrup until the entire surface is covered.

3. Develop a hypothesis discussing which dye you believe will diffuse faster across the corn syrup and the justification for your hypothesis. Be sure you validate your prediction with scientific reasoning.

Hypothesis:

Then, place a single drop of blue dye in the middle of the corn syrup....