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. Which vitamin is essential for blood clotting?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin K
• D. Vitamin D

Correct answer: C

Rationale: Vitamin K is essential for blood clotting as it plays a crucial role in the synthesis of clotting factors in the liver. Deficiency in vitamin K can result in impaired blood clotting and excessive bleeding. Vitamin K is necessary for the activation of proteins that are involved in the blood clotting process, making it a vital nutrient for maintaining proper hemostasis. Vitamin A (Choice A) is important for vision and immune function, Vitamin C (Choice B) is crucial for collagen synthesis and antioxidant protection, and Vitamin D (Choice D) is essential for calcium absorption and bone health. However, when it comes to blood clotting specifically, Vitamin K is the key vitamin involved.

3. What type of muscle is found in the walls of hollow organs like the intestines?

• A. Cardiac muscle
• B. Smooth muscle
• C. Skeletal muscle
• D. Voluntary muscle

Correct answer: B

Rationale: Smooth muscle is the correct type of muscle found in the walls of hollow organs like the intestines. It is responsible for movements such as peristalsis, aiding in the movement of food and other materials through the digestive system. Cardiac muscle (Choice A) is found in the heart and is responsible for the heart's contractions, not in hollow organs like the intestines. Skeletal muscle (Choice C) is attached to bones and responsible for voluntary movements, not in hollow organ walls. Voluntary muscle (Choice D) is another term for skeletal muscle, which is under conscious control, unlike smooth muscle in hollow organ walls.

4. Where is pseudostratified columnar epithelium primarily found?

• A. Skeletal muscle
• B. Bony skeleton
• C. External ears
• D. Bloodstream

Correct answer: C

Rationale: Pseudostratified columnar epithelium is a type of epithelial tissue found in the respiratory tract, including the lining of the trachea and bronchi. It is also found in the male reproductive system and parts of the auditory tube and external ear canal. Among the options provided, the external ears (option C) are the most relevant location for pseudostratified columnar epithelium. Skeletal muscle (option A) is primarily composed of muscle fibers, not epithelial tissue. The bony skeleton (option B) is composed of bone tissue. The bloodstream (option D) consists of blood cells and plasma, not epithelial tissue.

5. What is the functional group present in aldehydes?

• A. Hydroxyl
• B. Carbonyl
• C. Ester
• D. Amine

Correct answer: B

Rationale: The correct answer is B: Carbonyl. Aldehydes contain the functional group -CHO, which is a carbonyl group where a carbon atom is double-bonded to an oxygen atom and single-bonded to a hydrogen atom. This distinguishes aldehydes from other functional groups. Choice A, Hydroxyl (-OH), is not characteristic of aldehydes as it is found in alcohols. Choice C, Ester (-COOR), and choice D, Amine (-NH2), represent different functional groups not typically found in aldehydes. Therefore, the correct functional group present in aldehydes is the carbonyl group.

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