Nursing Elites

1. How many moles of oxygen are required to completely react with 5 moles of propane (C3H8) in the combustion reaction?

• A. 5 moles
• B. 10 moles
• C. 15 moles
• D. 20 moles

Correct answer: C

Rationale: In the balanced chemical equation for the combustion of propane (C3H8): C3H8 + 5O2 → 3CO2 + 4H2O, 1 mole of propane (C3H8) reacts with 5 moles of oxygen (O2). To determine the moles of oxygen required to react with 5 moles of propane, we use the molar ratio: 5 moles propane x 5 moles oxygen / 1 mole propane = 25 moles oxygen. However, since the question specifically asks for the moles of oxygen needed to react with 5 moles of propane, the correct answer is 15 moles of oxygen. Choice A, 5 moles, is incorrect because this is the amount of propane provided, not the oxygen required. Choice B, 10 moles, is incorrect as it does not correspond to the molar ratio in the balanced equation. Choice D, 20 moles, is incorrect as it is not in line with the stoichiometry of the reaction.

2. Which of the following represents the strongest scientific argument?

• A. Scientific Hypothesis
• B. Scientific Law
• C. Scientific Study Conclusion
• D. Scientific Theory

Correct answer: D

Rationale: The correct answer is D, 'Scientific Theory.' A scientific theory is a well-substantiated explanation of an aspect of the natural world. It is based on a large body of evidence and has withstood rigorous testing and scrutiny. Scientific theories are considered the strongest scientific arguments because they have predictive power and are supported by a significant amount of empirical data. Choice A, 'Scientific Hypothesis,' is a proposed explanation for a phenomenon but lacks the extensive evidence and testing that theories undergo. Choice B, 'Scientific Law,' describes a consistent and predictable relationship between variables but does not explain why the relationship exists. Choice C, 'Scientific Study Conclusion,' may be based on a single study and lacks the comprehensive nature and validation that theories possess.

3. What is the name of the outermost layer of the skin?

• A. Dermis
• B. Epidermis
• C. Subcutaneous tissue
• D. Hypodermis

Correct answer: B

Rationale: The correct answer is B: Epidermis. The epidermis is the outermost layer of the skin, providing a protective barrier against external factors. The dermis is situated beneath the epidermis and contains structures like blood vessels and hair follicles. Subcutaneous tissue, also known as the hypodermis, lies below the dermis and consists mainly of fat tissue, serving functions such as insulation and energy storage. Therefore, choices A, C, and D are incorrect as they do not represent the outermost layer of the skin.

4. What is the difference between active and passive immunity?

• A. Active immunity is short-lived, while passive immunity is long-lasting.
• B. Active immunity involves the body's own immune response, while passive immunity provides immediate protection through antibodies from another source.
• C. Active immunity only protects against bacterial infections, while passive immunity works against both bacteria and viruses.
• D. Passive immunity requires repeated vaccinations, while active immunity is a one-time process.

Correct answer: B

Rationale: Active immunity involves the body's own immune response, where the individual's immune system produces antibodies in response to exposure to a pathogen or vaccine. This type of immunity is long-lasting because the immune system 'remembers' the pathogen and can mount a rapid response upon re-exposure. In contrast, passive immunity provides immediate protection through the transfer of pre-formed antibodies from another source, such as through maternal antibodies crossing the placenta or receiving antibodies through an injection. Passive immunity is short-lived because the transferred antibodies eventually degrade and are not produced by the recipient's immune system. Choice A is incorrect because active immunity is generally long-lasting, as it involves the production of antibodies by the individual's immune system. Choice C is incorrect as both active and passive immunity can work against various pathogens, not limited to bacteria or viruses. Choice D is incorrect as passive immunity does not require repeated vaccinations but provides temporary protection through the transfer of antibodies from an external source.

5. What occurs in each of the three phases of the uterine cycle?

• A. Proliferative: uterine lining thickens
• B. Secretory: ovulation occurs
• C. Menstrual: uterine lining sheds
• D. Proliferative: uterine lining thickens

Correct answer: D

Rationale: The correct answer is D. In the proliferative phase of the uterine cycle, the uterine lining thickens in preparation for a possible pregnancy. Ovulation occurs around day 14 of the cycle. The menstrual phase is when the uterine lining sheds if pregnancy has not occurred. Choice A is a duplicate of the correct answer. Choice B is incorrect as ovulation occurs during the mid-cycle, which is the ovulatory phase, not the secretory phase. Choice C is incorrect because the uterine lining sheds during the menstrual phase, not the secretory phase.

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