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 is the primary function of the liver in the digestive system?

• A. To absorb water
• B. To produce bile
• C. To store glucose
• D. To regulate metabolism

Correct answer: B

Rationale: The liver's main function in the digestive system is to produce bile. Bile helps in the digestion and absorption of fats by emulsifying them, breaking down large fat globules into smaller droplets that can be acted upon by digestive enzymes. Choices A, C, and D are incorrect because the liver's primary role in the digestive system is not to absorb water, store glucose, or regulate metabolism. While the liver does have roles in metabolism and glucose regulation, its key function in digestion is bile production.

3. What happens to the acceleration of an object when the force acting on it is increased, assuming the mass remains constant?

• A. Acceleration increases
• B. Acceleration decreases
• C. Acceleration remains constant
• D. Acceleration becomes zero

Correct answer: A

Rationale: According to Newton's second law of motion, acceleration is directly proportional to the force acting on an object when the mass is constant. Therefore, if the force acting on an object is increased while the mass remains constant, the acceleration of the object will also increase. This relationship is described by the formula F = ma, where F is the force applied, m is the mass of the object, and a is the acceleration. When force increases, acceleration increases, and vice versa, as long as the mass stays the same. Choice B (Acceleration decreases) is incorrect because acceleration and force have a direct relationship. Choice C (Acceleration remains constant) is incorrect because acceleration changes in response to changes in force. Choice D (Acceleration becomes zero) is incorrect because increasing force does not make acceleration zero; it actually increases it.

4. Which of the following represents a form of potential energy?

• A. A moving car
• B. A spinning top
• C. A raised hammer
• D. A rolling ball

Correct answer: C

Rationale: A raised hammer represents potential energy as it possesses stored energy due to its position above the ground. When the hammer falls, this potential energy is converted into kinetic energy as it moves. In contrast, options A, B, and D involve objects already in motion, representing kinetic energy. Choice A, a moving car, is in motion and has kinetic energy. Choice B, a spinning top, is also in motion and exhibits kinetic energy. Choice D, a rolling ball, is already moving and thus has kinetic energy. Therefore, only choice C, a raised hammer, is the correct representation of potential energy among the given options.

5. During micturition, the process involves a combination of:

• A. Gravity alone
• B. Voluntary muscle contractions only
• C. Involuntary muscle contractions only
• D. Both voluntary and involuntary muscle contractions

Correct answer: D

Rationale: During micturition, which is the process of urination, both voluntary and involuntary muscle contractions are involved. Voluntary muscle contractions include the relaxation of the external urethral sphincter, allowing the release of urine, while involuntary muscle contractions involve the detrusor muscle in the bladder contracting to expel urine. Choices A, B, and C are incorrect because micturition is not solely dependent on gravity, voluntary muscle contractions, or involuntary muscle contractions alone. The correct answer is D as both types of muscle contractions are necessary for the complete process of urination.

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