Nursing Elites

1. How many mL of a 0 M stock solution of HCl should be added to water to create 250 mL of a 50 M solution of HCl?

• A. 31.25 mL
• B. 32 mL
• C. 30 mL
• D. 31.3 mL

Correct answer: B

Rationale: To prepare 250 mL of a 50 M solution of HCl, the formula V1 x C1 = V2 x C2 is used, where V1 is the volume of the stock solution, C1 is the concentration of the stock solution, V2 is the final volume of the desired solution, and C2 is the final concentration of the desired solution. Given V1 x 0 M = 250 mL x 50 M, solving for V1 results in V1 = (250 mL x 50 M) / 0 M = 32 mL. Therefore, 32 mL of the 0 M stock solution of HCl needs to be added to water to create a 250 mL solution of 50 M HCl. Choices A, C, and D are incorrect because they do not represent the accurate volume required for the dilution calculation based on the given concentrations and volumes in the problem.

2. Antibodies, crucial for immune defense, are produced by:

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Basophils

Correct answer: B

Rationale: Antibodies are produced by a specific type of lymphocyte known as B cells. B cells are a critical component of the adaptive immune system and are responsible for producing antibodies in response to pathogens. Neutrophils, monocytes, and basophils are types of white blood cells that are part of the innate immune response and do not have the function of producing antibodies. Neutrophils are primarily involved in phagocytosis, monocytes differentiate into macrophages and dendritic cells for antigen presentation, while basophils are involved in allergic reactions and parasitic infections.

3. What is the term for a solution that has a higher concentration of solute compared to another solution?

• A. Saturated solution
• B. Unsaturated solution
• C. Dilute solution
• D. Concentrated solution

Correct answer: D

Rationale: The correct answer is D, a concentrated solution. A concentrated solution contains a higher concentration of solute compared to another solution. This means there is a large amount of solute dissolved in the solvent, making it more concentrated than other solutions. Choices A, B, and C are incorrect. A saturated solution is one in which no more solute can be dissolved at a given temperature, an unsaturated solution can dissolve more solute at the given conditions, and a dilute solution has a low concentration of solute relative to the solvent.

4. Which of the following is the region of the brain that controls and regulates autonomic functions such as respiration, digestion, and heart rate?

• A. cerebellum
• B. medulla oblongata
• C. temporal lobe
• D. cerebral cortex

Correct answer: B

Rationale: The medulla oblongata is the correct answer. It is the region of the brain located at the base of the brainstem responsible for regulating autonomic functions such as respiration, digestion, and heart rate. These functions are essential for maintaining life. The cerebellum (Option A), temporal lobe (Option C), and cerebral cortex (Option D) do not control these autonomic functions. The cerebellum is mainly involved in coordination and balance, the temporal lobe is associated with memory and hearing, and the cerebral cortex is responsible for higher brain functions like thinking and decision-making.

5. Which of the following hormones helps regulate blood pressure by affecting kidney function?

• A. Insulin
• B. Testosterone
• C. Renin
• D. Estrogen

Correct answer: C

Rationale: Renin is the hormone that helps regulate blood pressure by affecting kidney function. It is released by the kidneys in response to low blood pressure or low blood volume. Renin plays a crucial role in the renin-angiotensin-aldosterone system, which is responsible for regulating blood pressure and fluid balance in the body. Insulin, testosterone, and estrogen do not directly impact blood pressure regulation through kidney function. Insulin is involved in regulating glucose metabolism, testosterone is a male sex hormone, and estrogen is a female sex hormone. Therefore, the correct answer is Renin (Choice C) because of its specific role in blood pressure regulation through kidney function.

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