Dialysis Experiment Observations and Tests

Mr. Kobe demonstrates a dialysis lab activity, explaining the properties of a semi-permeable membrane. The experiment involves testing whether glucose, starch, and iodine can pass through the dialysis membrane. Observations include color changes when starch and iodine mix, and glucose testing using strips. The results show a dark purplish color inside the dialysis bag, indicating iodine diffusion, while glucose presence is confirmed by a color change in the test strip. The video concludes with a summary of findings and encourages students to answer lab questions.

What is the primary characteristic of a dialysis membrane that makes it useful for experiments?

• It is impermeable to gases.

• It is fully permeable.

• It is semi-permeable.

• It is completely impermeable.

Which substances were used in the dialysis experiment setup?

• Salt, sugar, and water

• Glucose, protein, and salt

• Glucose, starch, and iodine

• Protein, starch, and iodine

What is the purpose of adding iodine to the cup in the experiment?

• To test for the presence of salt

• To test for the presence of protein

• To test for the presence of starch

• To test for the presence of glucose

What is the expected color change when starch and iodine mix?

• Green

• Blue

• Red

• Blackish with a purple tint

What does a color change in the glucose test strip indicate?

• Presence of protein

• Presence of iodine

• Presence of glucose

• Presence of starch

What was observed inside the dialysis bag after the experiment?

• No change

• A bright red color

• A dark purplish color

• A clear solution

What does the unchanged color of the iodine solution in the cup suggest?

• Starch diffused into the cup

• Iodine diffused into the dialysis bag

• Iodine did not diffuse into the dialysis bag

• Glucose diffused into the cup

What does a green color on the glucose test strip indicate?

• A large amount of glucose present

• No glucose present

• A small amount of glucose present

• A medium amount of glucose present

Why is it beneficial to let the experiment sit for a longer period?

• It ensures the solution remains unchanged

• It allows more time for the solution to evaporate

• It results in more vivid and clear results

• It prevents any reaction from occurring

What conclusion can be drawn from the color change in the glucose test strip after the experiment?

• Glucose did not diffuse out of the dialysis bag

• Glucose diffused out of the dialysis bag

• Starch diffused into the dialysis bag

• Iodine diffused out of the dialysis bag