Nursing Elites

1. Which of the following factors does NOT affect the rate of dissolution of a solute in a solvent?

• A. Temperature
• B. Pressure
• C. Surface area
• D. Particle size

Correct answer: B

Rationale: Pressure does not affect the rate of dissolution of a solute in a solvent. The factors that affect the rate of dissolution include temperature, surface area, and particle size. Temperature generally increases the rate of dissolution by providing more energy for the solute particles to break apart and mix with the solvent. Increasing the surface area of the solute by grinding it into smaller particles or increasing its contact area with the solvent can also speed up dissolution. Similarly, reducing the particle size of the solute can increase the rate of dissolution by providing more surface area for interaction with the solvent. Pressure, however, does not have a significant impact on the dissolution process and is not a factor that influences the rate at which a solute dissolves in a solvent.

2. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

3. Which of the following statements is true regarding a supersaturated solution?

• A. It is unstable and tends to crystallize
• B. It contains more solute than it could dissolve
• C. It has a higher concentration than a saturated solution
• D. It is rarely encountered in everyday solutions

Correct answer: A

Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.

4. What property of a wave determines the loudness of sound when heard by the human ear?

• A. Frequency
• B. Amplitude
• C. Wavelength
• D. Velocity

Correct answer: B

Rationale: The amplitude of a wave determines the loudness of sound when heard by the human ear. The greater the amplitude of a sound wave, the louder the sound will be perceived. Frequency (Choice A) refers to the number of wave cycles in a given time period. Wavelength (Choice C) is the distance between two corresponding points on a wave. Velocity (Choice D) is the speed at which the wave travels and does not directly affect the loudness of sound perceived by the human ear.

5. In the context of the cardiac cycle, what does the P wave on an electrocardiogram (ECG) represent?

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: A

Rationale: The P wave on an electrocardiogram (ECG) represents atrial depolarization, which signifies the electrical activation of the atria as they prepare to contract. During the cardiac cycle, atrial depolarization occurs first, leading to atrial contraction. Ventricular depolarization is represented by the QRS complex, not the P wave. Choices B, C, and D are incorrect because the P wave specifically corresponds to atrial depolarization, not ventricular depolarization, atrial repolarization, or ventricular repolarization.

Similar Questions