Nursing Elites

1. Which of the following is a weak acid commonly found in citrus fruits?

• A. Sulfuric acid (H₂SO₄)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Nitric acid (HNO₃)

Correct answer: C

Rationale: Citric acid is a weak acid commonly found in citrus fruits like lemons, oranges, and limes. It is responsible for the sour taste in these fruits. Sulfuric acid (option A), hydrochloric acid (option B), and nitric acid (option D) are all strong acids that are typically used in laboratory settings and industrial processes, not naturally found in citrus fruits. Therefore, the correct answer is option C.

2. How many neurons typically comprise a sensory pathway?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: C

Rationale: A sensory pathway generally consists of three neurons: a first-order neuron, a second-order neuron, and a third-order neuron. The first-order neuron carries sensory information from the periphery to the spinal cord or brainstem. The second-order neuron then transmits this information to the thalamus or cerebellum. Finally, the third-order neuron projects the sensory input to the cerebral cortex for processing and perception. Therefore, the correct answer is 3 (C). Choices A, B, and D are incorrect as they do not align with the typical structure of a sensory pathway involving three neurons.

3. How can the periodic table be used to predict the charge of an ion formed by an element?

• A. Look for elements with similar atomic weights.
• B. Identify the group number, which corresponds to the typical ionic charge.
• C. Calculate the difference between protons and electrons.
• D. Analyze the element's position within the period.

Correct answer: B

Rationale: The group number of an element on the periodic table corresponds to the number of valence electrons it has. Elements in the same group tend to form ions with the same charge. For example, elements in Group 1 typically form ions with a +1 charge, while elements in Group 17 typically form ions with a -1 charge. Therefore, by identifying the group number of an element, one can predict the typical ionic charge it will form. Choices A, C, and D are incorrect because predicting the charge of an ion is mainly based on the element's position in the periodic table, particularly the group number, which indicates the number of valence electrons and the typical ionic charge it may form.

4. Which of the following vessels is responsible for transporting blood from the heart to the lungs?

• A. Pulmonary vein
• B. Pulmonary artery
• C. Aorta
• D. Superior vena cava

Correct answer: B

Rationale: The correct answer is B, Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart's right ventricle to the lungs for oxygenation. This blood then undergoes the gas exchange process in the lungs, where carbon dioxide is removed, and oxygen is absorbed. The pulmonary vein, identified in choice A, carries oxygenated blood from the lungs back to the heart, which is the opposite direction of the blood flow specified in the question. Choice C, Aorta, is responsible for carrying oxygen-rich blood from the heart's left ventricle to the rest of the body, not to the lungs. Choice D, Superior vena cava, returns deoxygenated blood from the upper body to the heart's right atrium, but it does not transport blood specifically to the lungs as requested in the question.

5. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

• A. I⁻ is oxidized, Cr₂O₇²⁻ is reduced
• B. I⁻ is reduced, Cr₂O₇²⁻ is oxidized
• C. Both I⁻ and Cr₂O₇²⁻ are oxidized
• D. Both I⁻ and Cr₂O₇²⁻ are reduced

Correct answer: B

Rationale: In the given redox reaction, I⁻ is gaining electrons to form I₂, which means I⁻ is being reduced (undergoing reduction). On the other hand, Cr₂O₇²⁻ is losing electrons to form Cr³⁺, indicating that Cr₂O₇²⁻ is being oxidized (undergoing oxidation). Therefore, I⁻ is the reducing agent and Cr₂O₇²⁻ is the oxidizing agent. Choice A is incorrect because I⁻ is being reduced, not oxidized. Choice C is incorrect as both species cannot be oxidized in the same reaction. Choice D is incorrect as both species cannot be reduced in the same reaction.

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