Nursing Elites

1. Through which structure do the kidneys reabsorb water, salts, and nutrients and return them to the body?

• A. Renal artery
• B. Renal vein
• C. Nephron
• D. Glomerulus

Correct answer: C

Rationale: The question has been corrected to specify the structure responsible for reabsorbing water, salts, and nutrients in the kidneys. The correct answer is the nephron, which is the functional unit of the kidney that performs filtration and reabsorption processes. The renal artery brings blood into the kidney for filtration, the renal vein carries filtered blood away from the kidney, and the glomerulus is a part of the nephron where filtration occurs. Therefore, the nephron is the structure that reabsorbs substances and returns them to the body.

2. What is essential for an experiment to be considered successful?

• A. a reasonable hypothesis
• B. a well-written lab report
• C. data that others can reproduce
• D. computer-aided statistical analysis

Correct answer: C

Rationale: For an experiment to be considered successful, it is essential that the data collected and results obtained can be reproduced or replicated by others. This reproducibility ensures the reliability and validity of the experiment's findings. It allows for independent verification of the results and contributes to the overall scientific rigor of the study. While having a reasonable hypothesis, a well-written lab report, and computer-aided statistical analysis are important aspects of an experiment, the ability to reproduce the data is crucial for establishing the experiment's credibility and success. Without reproducibility, the findings may not be reliable, and the experiment's outcomes cannot be verified independently, leading to doubts about its validity.

3. What functional group is present in esters?

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

Correct answer: C

Rationale: The functional group present in esters is -COO-, which represents a carbonyl group bonded to an oxygen atom. This group is responsible for the characteristic fruity aroma of esters. Choice A, 'Hydroxyl,' refers to -OH, which is a characteristic group of alcohols, not esters. Choice B, 'Carbonyl,' is a broad term that includes various compounds with a C=O group, but specifically in esters, it is a carbonyl group bonded to an oxygen atom. Choice D, 'Amine,' refers to compounds containing a nitrogen atom bonded to hydrogen atoms or alkyl groups, which is not present in esters. Therefore, the correct answer is 'C: Ester.'

4. Which of the following describes how atomic radius varies across the periodic table?

• A. Atomic radius increases from top to bottom and left to right on the periodic table.
• B. Atomic radius increases from top to bottom and right to left on the periodic table.
• C. Atomic radius increases from top to bottom and toward the halogens on the periodic table.
• D. Atomic radius increases from top to bottom and toward the noble gases on the periodic table.

Correct answer: A

Rationale: Atomic radius tends to increase from top to bottom and left to right on the periodic table. This is because as you move down a group (top to bottom), new energy levels are added, increasing the distance of the outer electrons from the nucleus and thus increasing the size of the atom. On the other hand, as you move from left to right across a period, the number of protons and electrons increases, leading to a stronger nuclear charge that attracts the electrons closer to the nucleus, resulting in smaller atomic radii. Choice B is incorrect as atomic radius does not increase from right to left. Choices C and D are incorrect as they incorrectly associate the trend with specific groups of elements (halogens and noble gases) rather than the general trend observed on the periodic table.

5. 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.

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