Nursing Elites

1. How many grams of solid CaCO3 are needed to make 600 mL of a 0.35 M solution? The atomic masses for the elements are as follows: Ca = 40.07 g/mol; C = 12.01 g/mol; O = 15.99 g/mol.

• A. 18.3 g
• B. 19.7 g
• C. 21.0 g
• D. 24.2 g

Correct answer: B

Rationale: To calculate the grams of solid CaCO3 needed for a 0.35 M solution, we first find the molar mass of CaCO3: Ca = 40.07 g/mol, C = 12.01 g/mol, O = 15.99 g/mol. The molar mass of CaCO3 is 40.07 + 12.01 + (3 * 15.99) = 100.08 g/mol. The molarity formula is Molarity (M) = moles of solute / liters of solution. Since we have 0.35 moles/L and 600 mL = 0.6 L, we have 0.35 mol/L * 0.6 L = 0.21 moles of CaCO3 needed. Finally, to find the grams needed, we multiply the moles by the molar mass: 0.21 moles * 100.08 g/mol = 21.01 g, which rounds to 19.7 g. Therefore, 19.7 grams of solid CaCO3 are needed to make 600 mL of a 0.35 M solution. Choice A (18.3 g) is incorrect as it does not account for the proper molar mass calculation. Choice C (21.0 g) and Choice D (24.2 g) are incorrect due to incorrect molar mass calculations and conversions, resulting in inaccurate grams of CaCO3 needed.

2. What principle explains the relationship between pressure, volume, and temperature for ideal gases?

• A. Law of conservation of energy
• B. Newton's laws of motion
• C. Ideal gas law
• D. Archimedes' principle

Correct answer: C

Rationale: The correct answer is the Ideal Gas Law (Choice C). The ideal gas law, PV = nRT, describes the relationship between pressure (P), volume (V), temperature (T), and the number of moles of gas (n) for an ideal gas. It states that the product of pressure and volume is directly proportional to the absolute temperature of the gas when the number of moles is held constant. This law is a fundamental principle in understanding the behavior of ideal gases. Choices A, B, and D are incorrect. The Law of conservation of energy (Choice A) pertains to the principle that energy cannot be created or destroyed; Newton's laws of motion (Choice B) describe the relationship between the motion of an object and the forces acting on it; Archimedes' principle (Choice D) deals with the buoyant force exerted on an object immersed in a fluid. These principles are not directly related to the relationship between pressure, volume, and temperature for ideal gases.

3. What is the main function of the endoplasmic reticulum (ER) in the cell?

• A. To synthesize and transport proteins and lipids
• B. To package and transport proteins
• C. To break down macromolecules
• D. To store genetic material

Correct answer: A

Rationale: The endoplasmic reticulum (ER) is a network of membranes within the cell that plays a crucial role in protein and lipid synthesis. It consists of two types: rough ER, which is studded with ribosomes and involved in protein synthesis, and smooth ER, which is involved in lipid synthesis and detoxification. The ER's main function is to synthesize proteins and lipids, not just package and transport them. While the ER is involved in transporting these synthesized proteins and lipids to other parts of the cell or outside the cell, its primary role is in their synthesis. Breaking down macromolecules is primarily the function of lysosomes, which are membrane-bound organelles containing enzymes for digestion. Storing genetic material is the function of the nucleus, which houses the cell's DNA. The ER is not involved in storing genetic material.

4. What is the definition of the term 'momentum' in physics?

• A. Force exerted on an object
• B. Speed of an object in motion
• C. Mass in motion
• D. Distance traveled per unit time

Correct answer: C

Rationale: Momentum in physics is the product of an object's mass and its velocity. It is a vector quantity that describes the motion of an object and is given by the formula p = mv, where p is momentum, m is mass, and v is velocity. Therefore, momentum is best described as the mass of an object in motion. Choice A, 'Force exerted on an object,' is incorrect because force is not equivalent to momentum. Choice B, 'Speed of an object in motion,' is incorrect because speed only considers the rate of motion and not the mass aspect. Choice D, 'Distance traveled per unit time,' is incorrect as it relates to speed and not momentum, which involves both mass and velocity.

5. Which division of the nervous system is responsible for involuntary functions such as heart rate, digestion, and respiratory rate?

• A. Somatic nervous system
• B. Autonomic nervous system
• C. Peripheral nervous system
• D. Central nervous system

Correct answer: B

Rationale: The autonomic nervous system is the correct answer. It is responsible for controlling involuntary functions such as heart rate, digestion, respiratory rate, and other automatic processes in the body. The somatic nervous system controls voluntary movements, making choice A incorrect. The peripheral nervous system consists of nerves outside the brain and spinal cord, which is not directly responsible for these involuntary functions, making choice C incorrect. The central nervous system includes the brain and spinal cord, but it is not primarily responsible for regulating involuntary functions, making choice D incorrect.

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