Chemistry HESI A2 Practice Test

Correct Answer: B

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: C

Rationale: The given chemical equation shows aluminum replacing hydrogen in sulfuric acid, which is a single replacement reaction. In this type of reaction, one element displaces another in a compound. Here, Al replaces H in H2SO4 to form Al2(SO4)3 and HNO3. The other choices are incorrect because a decomposition reaction involves a single compound breaking down into simpler substances, a synthesis reaction involves two or more substances combining to form a new compound, and a double replacement reaction involves the exchange of ions between two compounds.

Correct Answer: B

Rationale: The correct answer is B: Amalgam. An amalgam is an alloy where mercury (Hg) is the solvent and another metal is dissolved in it. This is a common dental material. Electrum (A) is a natural alloy of gold and silver. Solder (C) is a metal alloy used to join other metals. Bronze (D) is an alloy of copper and tin.

Correct Answer: A

Rationale: To balance the equation, count the number of O atoms on both sides. If the equation is balanced, the coefficient of O should be the same on both sides. In this case, the coefficient of O is already 1 on both sides (since O appears only once on each side), so the correct answer is A. Choices B, C, and D are incorrect because changing the coefficient of O to any of those values would unbalance the equation.

Correct Answer: D

Rationale: Step 1: Define hydrogen bonding as a special type of dipole-dipole interaction. Step 2: Highlight that hydrogen bonding occurs between a hydrogen atom and highly electronegative atom (N, O, or F). Step 3: Emphasize that hydrogen bonding is stronger due to the large electronegativity difference between hydrogen and the other atom. Step 4: Compare the strength of hydrogen bonding to the other types of intermolecular forces. Step 5: Conclude that hydrogen bonding is the strongest intermolecular force due to its specific characteristics and stronger attraction compared to dipole-dipole interaction, London dispersion force, and Keesom interaction.