Nursing Elites

1. Which of the following is a strong acid?

• A. Acetic acid (CH₃COOH)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Carbonic acid (H₂CO₃)

Correct answer: B

Rationale: Hydrochloric acid (HCl) is a strong acid because it completely ionizes in water to produce hydrogen ions, leading to a high concentration of H⁺ ions in solution. This characteristic makes it a strong acid. Acetic acid (CH₃COOH), citric acid, and carbonic acid (H₂CO₃) are weak acids as they only partially ionize in water, resulting in a lower concentration of H⁺ ions compared to strong acids. Therefore, hydrochloric acid is the correct choice as a strong acid.

2. Which macromolecule will always contain nitrogen?

• A. Fatty acid
• B. Protein
• C. Lipid
• D. Carbohydrate

Correct answer: B

Rationale: The correct answer is B: Protein. Proteins always contain nitrogen, as it is a key element in amino acids, the building blocks of proteins. Fatty acids (choice A), lipids (choice C), and carbohydrates (choice D) do not always contain nitrogen. Fatty acids consist of long chains of hydrocarbons, lipids are mainly composed of carbon, hydrogen, and oxygen, and carbohydrates are composed of carbon, hydrogen, and oxygen as well, but not nitrogen.

3. Where does sperm maturation take place in the male reproductive system?

• A. Seminal vesicles
• B. Prostate gland
• C. Epididymis
• D. Vas Deferens

Correct answer: C

Rationale: Sperm maturation occurs in the epididymis, a coiled tube located on the back of each testicle. In the epididymis, sperm gain motility and the ability to fertilize an egg. It serves as a storage site for mature sperm until ejaculation. The seminal vesicles and the prostate gland contribute fluids to semen, enhancing sperm viability and motility. The vas deferens is responsible for transporting mature sperm from the epididymis to the urethra during ejaculation, but it is not where sperm maturation takes place. Therefore, the correct answer is the epididymis.

4. Which hormone, produced by the thyroid gland, plays a crucial role in regulating the body's metabolism, growth, and development?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: C

Rationale: Thyroxine, also known as T4, is a hormone produced by the thyroid gland that plays a crucial role in regulating the body's metabolism, growth, and development. It helps control the rate at which the body uses energy, affects protein synthesis, and influences the body's sensitivity to other hormones. Calcitonin (A) is another hormone produced by the thyroid gland, but its primary function is to regulate calcium levels in the blood. Parathyroid hormone (PTH) (B) is produced by the parathyroid glands and is involved in regulating calcium and phosphorus levels in the body. Insulin (D) is a hormone produced by the pancreas that helps regulate blood sugar levels.

5. When calcium chloride (CaCl2) dissolves in water, it separates into its ions (Ca2+ and Cl-). This is an example of:

• A. Chemical change
• B. Physical change
• C. Precipitation
• D. Neutralization

Correct answer: B

Rationale: When calcium chloride dissolves in water, it separates into its ions without forming a new substance, which is characteristic of a physical change. A physical change involves alterations in the substance's physical properties without changing its chemical composition. In this scenario, the chemical formula of calcium chloride remains unchanged, and only its physical state changes by creating ions in the solution. Therefore, the dissolution of calcium chloride in water is an example of a physical change. Choice A, 'Chemical change,' is incorrect because no new substances are formed during the dissolution process. Choice C, 'Precipitation,' is incorrect as precipitation involves the formation of an insoluble solid when two solutions react. Choice D, 'Neutralization,' is incorrect as it refers to a reaction between an acid and a base to form salt and water, which is not the case in the given scenario.

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