Nursing Elites

1. Which of the following types of matter changes in volume with changes in temperature and pressure?

• A. Liquid
• B. Gas
• C. Solid
• D. Plasma

Correct answer: B

Rationale: A gas changes its volume with changes in temperature and pressure due to the particles moving more rapidly at higher temperatures, and pressure affects the space between particles. Liquids have a relatively fixed volume but take the shape of their container. Solids have a definite shape and volume, so they do not change volume with changes in temperature and pressure. Plasma is a state of matter where particles are highly energized and do not have a fixed volume, but it does not exhibit volume changes with temperature and pressure variations.

2. To the nearest whole number, what is the mass of one mole of water?

• A. 16 g/mol
• B. 18 g/mol
• C. 20 g/mol
• D. 22 g/mol

Correct answer: B

Rationale: The molar mass of water (H₂O) is calculated by adding the atomic masses of two hydrogen atoms (each with a molar mass of approximately 1 g/mol) and one oxygen atom (with a molar mass of approximately 16 g/mol). Therefore, the molar mass of water is approximately 18 g/mol, making choice B the correct answer. Choice A (16 g/mol) is incorrect because it represents the molar mass of oxygen, not water. Choices C (20 g/mol) and D (22 g/mol) are incorrect as they do not correspond to the molar mass of water.

3. Where would you expect tap water to fall on the pH scale?

• A. Between 1 and 3
• B. Between 4 and 6
• C. Between 6 and 8
• D. Between 8 and 10

Correct answer: C

Rationale: Tap water typically falls within the pH range of 6 to 8, making it slightly acidic to neutral. Most municipal water systems aim to provide water that is safe for consumption and falls within this pH range. A pH level of 7 is considered neutral, so tap water may vary slightly on either side of this number but typically remains within the 6 to 8 range to ensure it is safe for consumption. Choices A, B, and D are incorrect because tap water is not expected to have a pH as low as 1-3 (highly acidic) or as high as 8-10 (alkaline); it usually falls within the slightly acidic to neutral range, hence falling between 6 and 8 on the pH scale.

4. What determines polarity in a molecule?

• A. Bond length
• B. Bond strength
• C. Electronegativity
• D. Molecular weight

Correct answer: C

Rationale: Polarity in a molecule is determined by the difference in electronegativity between the atoms forming the bond. The greater the difference in electronegativity, the more polar the bond and molecule become. This difference leads to an uneven distribution of electron density within the bond, creating partial positive and negative charges on the atoms involved. Choices A, B, and D are incorrect. Bond length and strength do not determine polarity, and molecular weight is not directly related to the polarity of a molecule.

5. What distinguishes one allotrope from another?

• A. Arrangement of atoms
• B. Gram atomic mass
• C. Physical state
• D. Stability

Correct answer: A

Rationale: Allotropes are different forms of the same element that exist in the same physical state but have different structures. The arrangement of atoms is what distinguishes one allotrope from another, determining their unique properties and characteristics. Gram atomic mass (Choice B) is a constant value for a specific element and does not change between different allotropes. Physical state (Choice C) refers to whether a substance is a solid, liquid, or gas, which can be the same for different allotropes of an element. Stability (Choice D) can vary between different allotropes, but it is not what always differentiates one allotrope from another. Therefore, the correct answer is the arrangement of atoms, as it is the key factor that varies across different allotropes.

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