Question

A selectively permeable membrane divides a container in half. One half of the container. Side A, is filled with a starch solution, while whe other half, Side B, is filled with an iodine tincture. Starch is a large macromolecule that forms a milky white solution when dissolved. An iodine tincture contains very small iodide ions and is a brown solution. lodide ions turn dark blue when they react with starch molecules After several hours, Side A is dark blue, while Side B is brown. Which statement describes the diffusion of solutes through the membrane? ded the iodide ions, but the starch mol O Both the starch molecules and the iodide ions diffused through the membrane O The membrane excluded both the starch molecules and the iodide ions O The membrane excluded the starch molecules, but the iodide ions diffused through

Answer 1

The membrane excluded the starch molecules, but the iodide ions diffused through

Step-by-step explanation:

The diffusion of substances always occurs from the region of higher concentration to the region of their lower concentration.

According to the given information, starch is a large macromolecule. Reaction of iodide and starch turns iodide ions dark blue. Since the side A of the container turned dark blue, it means that iodide ions diffused through the membrane from side B to side A. It turned the side A dark blue.

If starch would have diffused from side A to side B through the membrane, the side B would also have turned dark blue. However, side B had a brown solution. Therefore, the large molecules of starch were not allowed to pass through the membrane.