Nursing Elites

1. In what type of covalent compounds are dispersion forces typically found?

• A. Polar
• B. Non-polar
• C. Ionic
• D. Hydrogen

Correct answer: B

Rationale: Dispersion forces, also known as London dispersion forces, are the weakest intermolecular forces that occur in non-polar covalent compounds. These forces result from temporary shifts in electron density within molecules, creating temporary dipoles. As a result, non-polar molecules, which lack a permanent dipole moment, can experience these dispersion forces. Polar compounds exhibit stronger intermolecular forces such as dipole-dipole interactions or hydrogen bonding, while ionic compounds involve electrostatic interactions between ions. Therefore, the correct answer is non-polar (choice B). Choices A, C, and D are incorrect because dispersion forces are typically found in non-polar covalent compounds, not polar, ionic, or hydrogen-bonded compounds.

2. What are the products of the combustion of a hydrocarbon?

• A. Water and carbon dioxide
• B. Water and oxygen
• C. Hydrogen and carbon monoxide
• D. Carbon dioxide and oxygen

Correct answer: A

Rationale: When a hydrocarbon undergoes combustion, it reacts with oxygen to produce water and carbon dioxide as the main products. The general chemical equation for the combustion of a hydrocarbon is hydrocarbon + oxygen → carbon dioxide + water. Therefore, the correct answer is 'Water and carbon dioxide.' Choices B, C, and D are incorrect because water and carbon dioxide are the primary products of hydrocarbon combustion, not water and oxygen, hydrogen and carbon monoxide, or carbon dioxide and oxygen.

3. What are the 3 types of radiation in nuclear chemistry?

• A. Alpha, Beta, Delta
• B. Alpha, Beta, Gamma
• C. Gamma, Beta, Delta
• D. Delta, Beta, Gamma

Correct answer: B

Rationale: The correct answer is B: Alpha, Beta, Gamma. In nuclear chemistry, the 3 types of radiation are alpha, beta, and gamma radiation. Alpha radiation consists of helium nuclei, beta radiation involves electrons or positrons, and gamma radiation is electromagnetic radiation of high frequency. Choice A is incorrect because 'Delta' is not a type of radiation in nuclear chemistry. Choice C is incorrect as it does not list alpha radiation. Choice D is incorrect as it lists the types in the wrong order and includes 'Delta' instead of alpha radiation.

4. Which intermolecular force is the strongest?

• A. Dipole interactions
• B. Dispersion forces
• C. Hydrogen bonding
• D. Van der Waals forces

Correct answer: C

Rationale: Hydrogen bonding is the strongest intermolecular force due to its specific interaction between a hydrogen atom and a highly electronegative atom like nitrogen, oxygen, or fluorine. This type of bonding results in a very strong attraction between molecules, making it the strongest intermolecular force among the options provided. Dipole interactions (choice A) are weaker than hydrogen bonding as they occur between polar molecules. Dispersion forces (choice B) are the weakest intermolecular forces and are caused by temporary fluctuations in electron distribution. Van der Waals forces (choice D) are a broader term that encompasses dipole interactions and dispersion forces, making them weaker than hydrogen bonding.

5. Here are the solubilities of four substances at 0°C, in grams of solute per 100 mL of water. If the temperature increases to 20°C, what would you expect to happen to the solubility figures?

• A. Citric acid and potassium phosphate will decrease; nitrogen and oxygen will increase.
• B. Citric acid and potassium phosphate will increase; nitrogen and oxygen will decrease.
• C. All four figures will increase.
• D. All four figures will decrease.

Correct answer: C

Rationale: Solubility generally tends to increase with temperature for most solid solutes in liquid solvents due to higher kinetic energy leading to better solute-solvent interactions. As the temperature increases from 0°C to 20°C, all four solubility figures are expected to increase. Choice A is incorrect because solubility tends to increase with temperature. Choice B is incorrect as well for the same reason. Choice D is incorrect because the solubility of solid solutes typically increases with temperature.

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