Question

1. in the box below, there is a semi-permeable membrane in the middle that the small black molecules can pass through, but the larger white molecules cannot. draw the result of diffusion in the box on the right

Explanation:

Step1: Analyze molecule movement

Small black molecules (let's count them: initially left has, say, \( n \) black molecules, right has 0; white molecules: left has \( m \) white, right has 0. Semi - permeable membrane allows black to pass, white not.

Step2: Apply diffusion principle

Diffusion is movement from high to low concentration. So black molecules will spread evenly across both sides (left and right boxes). White molecules stay only on the left (since they can't pass the membrane).

First, count the number of small black molecules (let's assume from the diagram: left has, for example, 15 black molecules) and white molecules (left has 8 white molecules). After diffusion, the white molecules remain on the left side (same number, 8) in the left box of the right diagram. The black molecules will be distributed such that half (or as per equal concentration) are on the left and half on the right. So in the right - hand diagram's left box, we have 8 white molecules and 7 - 8 black molecules (depending on exact count), and in the right - hand diagram's right box, we have 7 - 8 black molecules (and 0 white molecules, since white can't cross).

To draw: In the left compartment of the right box, draw the same number of white circles (large) as in the left original box, and half (approx) of the black dots (small). In the right compartment of the right box, draw the other half of the black dots (small), and 0 white circles.

Answer:

In the right - hand diagram:

• Left compartment: Same number of large white circles (as left original) and half (approx) of small black dots.
• Right compartment: Half (approx) of small black dots (no large white circles).

(Note: The actual drawing should reflect the equal distribution of small black molecules across both compartments, while large white molecules stay in the left compartment.)