1.
What is the purpose of IKI in the lab?
Correct Answer
C. To indicate the presence of starch
Explanation
IKI (iodine-potassium iodide) is commonly used in laboratory experiments to indicate the presence of starch. When IKI comes into contact with starch, it forms a dark blue-black color. This reaction is due to the formation of a complex between iodine and the helical structure of starch molecules. Therefore, the purpose of IKI in the lab is to detect the presence of starch by observing the color change in the solution.
2.
In this lab the dialysis tubing represents
Correct Answer
B. Plasma Membrane
Explanation
The dialysis tubing represents the plasma membrane. The plasma membrane is a selectively permeable barrier that surrounds the cell and regulates the movement of substances in and out of the cell. Dialysis tubing is a semi-permeable membrane that allows the passage of small molecules, similar to the plasma membrane. Therefore, using dialysis tubing in the lab can simulate the functions and properties of the plasma membrane.
3.
Which of the following is true of sucrose?
Correct Answer
C. It is the same as starch
4.
Which molecule is larger, glucose or IKI?
Correct Answer
B. Glucose
Explanation
Glucose is larger than IKI. Glucose is a monosaccharide with a molecular formula of C6H12O6, while IKI (iodine potassium iodide) is a compound consisting of iodine and potassium iodide. Glucose has a larger molecular structure with six carbon atoms, while IKI is a smaller compound. Therefore, glucose is the larger molecule compared to IKI.
5.
A 0.2 M solution of sucrose will have
Correct Answer
D. .2 moles of sucrose per L of solution
Explanation
A 0.2 M solution of sucrose means that there are 0.2 moles of sucrose dissolved in 1 liter of solution. The concentration of the sucrose is given in moles per liter of solution, not moles per liter of water. Therefore, the correct answer is ".2 moles of sucrose per L of solution."
6.
Which solution list below is most hypertonic relative to distilled water?
Correct Answer
D. 0.6 M sucrose
Explanation
The solution that is most hypertonic relative to distilled water is 0.6 M sucrose. Hypertonic solutions have a higher solute concentration compared to the surrounding solution. In this case, the sucrose concentration increases from 0.0 M to 0.6 M, indicating a higher solute concentration. Therefore, 0.6 M sucrose is the most hypertonic solution among the given options.
7.
How is the presence of glucose detected?
Correct Answer
A. Glucose test strip
Explanation
The presence of glucose is detected using a glucose test strip. This strip contains a chemical reagent that reacts with glucose in a sample, producing a color change. By comparing the color of the strip with a color chart, the concentration of glucose can be determined. The other options, IKI (iodine-potassium iodide) and change in mass, are not commonly used methods for detecting glucose. Therefore, the correct answer is the glucose test strip.
8.
In the lab how can you tell whether the dialysis bags gained or lost water?
Correct Answer
C. By the change in mass
Explanation
In the lab, the most reliable way to determine whether the dialysis bags gained or lost water is by measuring the change in mass. This is because water has a known density, and any change in mass would indicate a corresponding change in the amount of water present in the dialysis bags. Changes in color or volume may not necessarily correlate with changes in water content, making them less accurate indicators.
9.
Osmosis is
Correct Answer
D. The diffusion of water
Explanation
Osmosis is the process of diffusion of water molecules across a selectively permeable membrane. It occurs when there is a difference in the concentration of solute molecules on either side of the membrane. Water moves from an area of lower solute concentration to an area of higher solute concentration in order to equalize the concentration on both sides. Therefore, the correct answer is "The diffusion of water."
10.
How does water move?
Correct Answer
A. Always from higher potential to lower potential
Explanation
Water moves from higher potential to lower potential due to the principle of diffusion. This means that water molecules will naturally move from an area of higher concentration (higher potential) to an area of lower concentration (lower potential) until equilibrium is reached. This movement occurs through a process called osmosis, where water molecules pass through a semi-permeable membrane to equalize the concentration on both sides. Therefore, water will always move from a region of higher potential to a region of lower potential.