Q: Which equation best represents the calculation for percent change in mass of a dialysis sac after incubation?

$$\frac{\text{final mass} - \text{initial mass}}{\text{initial mass}} \times 100$$

Q: If the initial mass of a dialysis sac is 5.0 g and the final mass after incubation is 6.2 g, what is the percent change in mass?

$$\frac{6.2 - 5.0}{5.0} \times 100 = 24\%$$

Question 1

A dialysis sac containing 10% glucose is placed in a beaker of distilled water. After 45 minutes, the sac gains weight. Which process best explains this observation?

Accepted Answer

Osmosis of water into the sac

Question 2

Which of the following best describes a hypotonic solution in the context of the red blood cell experiment?

Accepted Answer

A solution with a lower solute concentration than the cell cytoplasm

Question 3

If a dialysis sac filled with 40% glucose is placed in distilled water, what is the expected net movement of water after 45 minutes?

Accepted Answer

Water will move into the sac

Question 4

A student tests for the presence of starch in a beaker after 45 minutes using Lugol's iodine solution. The solution remains yellow. What does this indicate?

Accepted Answer

Starch is absent from the beaker

Question 5

Which equation best represents the calculation for percent change in mass of a dialysis sac after incubation?

Accepted Answer

$$\frac{	ext{final mass} - 	ext{initial mass}}{	ext{initial mass}} 	imes 100$$

Question 6

In the experiment, Benedict's solution is used to test for glucose. What color change indicates a positive result?

Accepted Answer

Blue to green, yellow, or rust

Question 7

A dialysis sac containing 10% NaCl is placed in distilled water. After 45 minutes, silver nitrate is added to the beaker and a white precipitate forms. What does this indicate?

Accepted Answer

NaCl diffused out of the sac into the beaker

Question 8

Which of the following best describes the function of a semipermeable membrane in the dialysis experiment?

Accepted Answer

Allows only water and small solutes to pass, but not large molecules like starch

Question 9

If a red blood cell is placed in a hypertonic solution, what is the expected change in cell shape?

Accepted Answer

The cell will shrink and become crenated

Question 10

After 45 minutes, a dialysis sac containing boiled starch is tested with Lugol's iodine solution in the beaker. No color change is observed. What is the most likely explanation?

Accepted Answer

Starch molecules are too large to pass through the membrane

Question 11

Which of the following is a correct application of diffusion in the context of the experiment?

Accepted Answer

Glucose moves from an area of higher concentration to lower concentration

Question 12

A dialysis sac containing 10% glucose and 10% NaCl is placed in distilled water. After 45 minutes, which substances are most likely to be found in the beaker?

Accepted Answer

Glucose and NaCl

Question 13

Which test would you use to confirm the presence of glucose in a solution after the experiment?

Accepted Answer

Add Benedict's solution and heat

Question 14

If the initial mass of a dialysis sac is 5.0 g and the final mass after incubation is 6.2 g, what is the percent change in mass?

Accepted Answer

$$\frac{6.2 - 5.0}{5.0} 	imes 100 = 24\%$$

Question 15

Why is it important to use a control (such as distilled water) in the dialysis experiment?

Accepted Answer

To ensure that only the variable being tested affects the results

Question 16

Which of the following best explains why boiled starch does not diffuse through the dialysis membrane?

Accepted Answer

Boiled starch molecules are too large to pass through the pores of the membrane

Question 17

A dialysis sac containing 10% glucose is placed in a beaker with 10% NaCl. After 45 minutes, which test would confirm the presence of NaCl in the sac?

Accepted Answer

Add silver nitrate to the sac solution

Question 18

In the context of the experiment, which statement about osmosis is correct?

Accepted Answer

Osmosis is the movement of water molecules from low to high solute concentration across a semipermeable membrane

Question 19

A dialysis sac containing 10% glucose is placed in a beaker of 40% glucose. After 45 minutes, what is the expected net movement of water?

Accepted Answer

Water will move out of the sac

Question 20

Which of the following is a real-world application of the principles demonstrated in the dialysis experiment?

Accepted Answer

Medical dialysis for patients with kidney failure

Diffusion and Osmosis: Experimental Procedures and Analysis

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