An aqueous mixture containing starch (a colloid), NaCl, glucose, and albumin (a colloid) is placed in a dialyzing bag and immersed in distilled water. Which of the following correctly describes the location of the indicated substance after dialysis?

A-albumin, inside
B-starch outside
C-albumin inside and outside
D-water inside only
E-starch inside and outside

A-Albumin inside because it is a colloid and cannot pass through a semipermeable membrane.

To determine the location of each substance after dialysis, we need to understand the principles behind dialysis.

Dialysis is a process that involves the separation of substances based on their size and solubility. It utilizes a semi-permeable membrane that allows the passage of small ions and molecules while blocking larger molecules. In this case, the dialyzing bag acts as the semi-permeable membrane.

Given the nature of the substances in the mixture:
- Starch and albumin are both colloids, which are relatively large molecules.
- NaCl and glucose are smaller solutes.

When the mixture is placed in a dialyzing bag and immersed in distilled water, the dialysis process begins. Water molecules (solvent) move across the dialyzing bag through osmosis, from an area of lower solute concentration (distilled water) to an area of higher solute concentration (inside the bag).

Now let's analyze the substances one by one:

1. Starch:
Starch is a colloid, a relatively large molecule. It cannot pass through the semi-permeable membrane. Therefore, starch will remain outside the bag. The correct option is B - starch, outside.

2. NaCl:
NaCl is a small solute that can pass through the semi-permeable membrane. It will diffuse from the area of higher concentration (inside the bag) to the area of lower concentration (distilled water) through the process of diffusion. However, the question does not indicate any specific location for NaCl after dialysis.

3. Glucose:
Glucose is also a small solute that can pass through the semi-permeable membrane. It will diffuse from the area of higher concentration (inside the bag) to the area of lower concentration (distilled water) through the process of diffusion. However, the question does not indicate any specific location for glucose after dialysis.

4. Albumin:
Albumin is another colloid, similar to starch. As a relatively large molecule, it cannot pass through the semi-permeable membrane. Therefore, albumin will remain inside the bag. The correct option is A - albumin, inside.

Based on this analysis, the correct answer is:
A - albumin, inside (option A).

During dialysis, small molecules such as water, glucose, and NaCl are able to pass through the dialyzing membrane, while larger molecules like starch and albumin are not able to pass through.

Given that starch is a large molecule and albumin is also a large colloid, they will both remain inside the dialyzing bag and not pass through the membrane.

On the other hand, water, as a small molecule, will be able to pass through the dialyzing membrane and be present both inside and outside the dialyzing bag.

Therefore, the correct answer is E - starch will be inside and outside the dialyzing bag, while albumin will be inside only, and water will be both inside and outside.