HESI A2 Chemistry Questions

Correct Answer: B

Rationale: The correct answer is B: Condensation. Condensation is the process in which a gas turns into a liquid by losing heat energy. During condensation, gas molecules slow down and come closer together, forming liquid droplets. Sublimation (A) is the process of a solid turning directly into a gas without passing through the liquid phase. Evaporation (C) is the process of a liquid turning into a gas. Deposition (D) is the process in which a gas transforms directly into a solid without becoming a liquid first.

Correct Answer: C

Rationale: The correct answer is C: Argon. Noble gases are elements in Group 18 of the periodic table with full valence electron shells, making them stable and non-reactive. Argon is a noble gas with 8 valence electrons, fulfilling the octet rule. Hydrogen (A) is a nonmetal in Group 1, Fluorine (B) is a halogen in Group 17, and Nitrogen (D) is a nonmetal in Group 15, none of which are noble gases.

Correct Answer: B

Rationale: The correct answer is B: joule. Joule is the SI unit of energy, defined as the work done when a force of one newton is applied over a distance of one meter. Ohm (A) is the SI unit of electrical resistance, henry (C) is the SI unit of inductance, and newton (D) is the SI unit of force. Therefore, the correct choice is B as it specifically represents energy in the SI system.

Correct Answer: A

Rationale: The correct answer is A: By lowering the pressure. When pressure is decreased, the boiling point of water also decreases, allowing it to boil at room temperature. Lower pressure reduces the amount of energy needed for water molecules to escape into the gas phase. Increasing pressure (Choice B) raises the boiling point, making it harder to boil at room temperature. Decreasing the volume (Choice C) is not directly related to the boiling point of water. Raising the boiling point (Choice D) would require increasing pressure, contradicting the premise of boiling at room temperature.

Correct Answer: C

Rationale: The correct answer is C: aluminum. Specific heat capacity is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. Aluminum has a small specific heat capacity compared to water, wood, and glass. This is because aluminum has a lower heat capacity due to its lower mass and atomic structure. Water, on the other hand, has a high specific heat capacity due to its hydrogen bonding, making it an excellent heat reservoir. Wood and glass have higher specific heat capacities compared to aluminum, as they are denser materials and require more heat energy to raise their temperatures.