Diffusion and Starch Indicator Experiment

The video tutorial demonstrates diffusion through a selectively permeable membrane using a simple experiment. It involves preparing a starch solution in a plastic bag and immersing it in a beaker with iodine solution. Over time, the iodine diffuses into the bag, turning the starch solution blue-black, indicating the presence of starch. This change confirms the movement of iodine molecules from a higher to a lower concentration, illustrating diffusion.

What is the main concept demonstrated in this experiment?

• Evaporation of water

• Filtration through a membrane

• Diffusion through a selectively permeable membrane

• Osmosis through a permeable membrane

Which of the following is NOT a material required for the experiment?

• Plastic bag

• Large beaker

• Hot water

• Starch solution

What is used to create the starch solution?

• Sugar and cold water

• Salt and hot water

• Corn flour and cold water

• Corn flour and hot water

How is the starch solution sealed in the plastic bag?

• With tape

• With a string

• With a clip

• With a rubber band

What is added to the water in the beaker to test for starch presence?

• Salt solution

• Iodine solution

• Vinegar

• Baking soda

What is the purpose of adding iodine solution to the beaker?

• To dissolve the starch

• To act as an indicator for starch

• To increase the water temperature

• To change the water color

What indicates that diffusion has occurred in the experiment?

• The iodine solution evaporates

• The starch solution in the bag turns blue-black

• The water in the beaker turns blue-black

• The plastic bag dissolves

What does the color change in the starch solution signify?

• The iodine has moved into the bag

• The water has become acidic

• The plastic bag has leaked

• The starch has evaporated

What happens to the iodine molecules during the experiment?

• They evaporate

• They dissolve the plastic bag

• They remain in the beaker

• They move into the plastic bag

How does the duration of the experiment affect the results?

• The duration has no effect

• The longer the duration, the less visible the color change

• The longer the duration, the more intense the color change

• The duration causes the plastic bag to dissolve