Nursing Elites

1. What is the law of conservation of energy?

• A. Energy cannot be created, only destroyed
• B. Energy can be created but not destroyed
• C. Energy can neither be created nor destroyed, only transformed from one form to another
• D. Energy is always created in any process

Correct answer:

Rationale: According to the law of conservation of energy, the total energy in a closed system remains constant; it can change forms but cannot be created or destroyed.

2. Vaccines work by stimulating the immune system to develop memory without causing full-blown illness. What type of molecule in a vaccine typically triggers the immune response?

• A. Toxins produced by the pathogen
• B. Live, attenuated (weakened) forms of the pathogen
• C. Inactivated (dead) forms of the pathogen
• D. Antigens (specific molecules) from the pathogen

Correct answer: D

Rationale: The correct answer is D: Antigens (specific molecules) from the pathogen. Vaccines contain antigens, which are specific molecules from the pathogen that trigger the immune response without causing the full-blown illness. By presenting these antigens to the immune system, vaccines stimulate the production of memory cells that can recognize and combat the pathogen in the future. Options A, B, and C are incorrect because vaccines typically do not contain toxins, live attenuated forms, or inactivated forms of the pathogen. Instead, they contain specific antigens to induce an immune response without causing the actual disease.

3. The van't Hoff factor (i) accounts for the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be...

• A. 0
• B. Less than 1
• C. 1
• D. More than 1

Correct answer: C

Rationale: The van't Hoff factor (i) is used to account for the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, such as a strong electrolyte, i would be equal to the total number of ions produced by the dissociation. Since the compound dissociates completely, it forms an equal number of ions, resulting in an i value of 1. Therefore, the correct answer is C: 1.

4. When water boils, it changes from a liquid to a gas. This is an example of a:

• A. Chemical reaction
• B. Physical change
• C. Nuclear reaction
• D. Biological process

Correct answer: B

Rationale: Physical change - Boiling water involves a change in state, not the chemical composition of the molecules. Chemical reactions involve breaking and forming new bonds, which is not the case here.

5. A ball is thrown horizontally off a cliff with a speed of 10 m/s. What is the horizontal distance the ball travels before hitting the ground?

• A. 10 m
• B. 20m
• C. 30m
• D. Cannot be determined without knowing the height of the cliff

Correct answer: C

Rationale: When a ball is thrown horizontally, its horizontal velocity remains constant throughout its motion. The time taken to hit the ground is determined by the vertical motion, which is independent of the horizontal velocity. Therefore, the horizontal distance traveled by the ball is determined by the horizontal velocity and the time taken to hit the ground. In this case, the horizontal distance is calculated as distance = velocity × time = 10 m/s × time. Since the horizontal velocity is 10 m/s and the time taken to hit the ground is determined by the vertical motion, the horizontal distance traveled by the ball is 10 m/s × time. Without knowing the height of the cliff, we can still determine the horizontal distance traveled by the ball, which is 10 m/s × time.

6. If you compare a 1 M solution of NaCl to a 1 M solution of glucose (C6H12O6) in water, which solution would have the higher boiling point?

• A. The NaCl solution
• B. The glucose solution
• C. They would have the same boiling point
• D. It depends on the temperature

Correct answer: A

Rationale: The correct answer is A. When a solute is added to a solvent, it raises the boiling point of the solution due to the phenomenon of boiling point elevation. In this case, NaCl is an ionic compound that dissociates into Na+ and Cl- ions in water, leading to more particles in solution compared to glucose, which remains as individual molecules. Since NaCl forms more particles, it causes a greater boiling point elevation, resulting in the NaCl solution having the higher boiling point. Glucose, being a non-electrolyte, does not dissociate and therefore does not contribute as many particles to the solution as NaCl does. Therefore, the NaCl solution would have the higher boiling point.

Similar Questions