HESI A2 Chemistry Questions

Correct Answer: A

Rationale: The correct answer is A: Hydrogen acceptors. Bases or alkaline solutions are known as hydrogen acceptors because they can accept a hydrogen ion (H+) to form water. This process is known as neutralization. Choices B and C are incorrect because alkaline solutions are not solutions of low pH or hydrogen donors. Choice D, amphoteric, refers to substances that can act as both acids and bases, which is not the definition of bases or alkaline solutions.

Correct Answer: C

Rationale: The correct answer is C because an acid reacts with bases to form salt and water through a neutralization reaction. This property is known as the acidic property. Choice A (Bitter taste) is incorrect as acids generally taste sour, not bitter. Choice B (Slippery feel) is incorrect as this describes the texture of bases, not acids. Choice D (Sweet taste) is incorrect as acids typically taste sour, not sweet. In summary, the property of reacting with bases is unique to acids, distinguishing them from other substances.

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: B

Rationale: The correct answer is B: periods. Periods are the horizontal rows in the periodic table that represent the energy levels of the elements. They indicate the number of electron shells present in an element. Groups (A) are the vertical columns, representing elements with similar chemical properties. Families (C) are also vertical columns that share similar characteristics. Sets (D) is a generic term and not specific to the periodic table structure. Therefore, the correct term for the horizontal rows of the periodic table is periods.

Correct Answer: A

Rationale: The correct answer is A: Decomposition reaction. In a decomposition reaction, a compound is broken down into its individual components. This process involves the breaking of chemical bonds within the compound, resulting in the formation of simpler substances. This type of reaction is characterized by one reactant and multiple products. In contrast, the other choices - B: Combustion reaction, C: Neutralization reaction, and D: Single displacement reaction - do not involve the breaking down of a compound into its components but rather involve different types of chemical transformations. Combustion reaction involves the reaction of a substance with oxygen to produce heat and light, neutralization reaction involves the reaction between an acid and a base to form water and a salt, and single displacement reaction involves the replacement of one element in a compound by another element.