Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: The correct answer is C: Hydrogen bonding. Hydrogen bonding is the strongest intermolecular force due to the high electronegativity difference between hydrogen and elements like nitrogen, oxygen, or fluorine, leading to a strong partial positive charge on hydrogen. This allows for a strong attraction with the partial negative charge on the electronegative atom of another molecule. Dipole interactions (A) are weaker than hydrogen bonding, dispersion forces (B) are the weakest intermolecular force, and Van der Waals forces (D) are a broad term that encompasses all intermolecular forces, including hydrogen bonding.

Correct Answer: C

Rationale: The correct answer is C: Synthesis. In a synthesis reaction, two or more substances combine to form a single compound. When two elements combine to form a product, it is a classic example of a synthesis reaction. During synthesis, the reactants lose their individual properties and form a new compound. A) Decomposition involves a single compound breaking down into two or more simpler substances. B) Combustion is a chemical process involving a fuel and an oxidant, resulting in the release of energy. D) Double replacement involves the exchange of ions between two compounds to form two new compounds. Therefore, the correct answer is C because it best describes the scenario of two elements combining to form a product.

Correct Answer: D

Rationale: The correct answer is D: Molar mass. One mole of a substance represents the molar mass, which is the mass of one mole of that substance in grams. This is calculated by summing the atomic masses of all the atoms in the chemical formula. The molar mass is expressed in g/mol and is a fundamental concept in chemistry for performing various calculations. A: Atomic mass refers to the mass of an individual atom of an element, not one mole of a substance. B: Mass number refers to the total number of protons and neutrons in an atom's nucleus, not the mass of one mole of a substance. C: Molecular weight is the sum of the atomic weights of the atoms in a molecule, not the mass of one mole of a substance.

Correct Answer: A

Rationale: The correct answer is A: Decomposition. This reaction involves breaking down a compound into simpler components through the use of heat, light, or electricity. Decomposition reactions are the opposite of synthesis reactions, where compounds are formed from simpler substances. Combustion involves the reaction of a substance with oxygen to produce heat and light. Single replacement reactions occur when one element replaces another in a compound. In this context, only decomposition aligns with the process of breaking down a compound into its component parts.

Correct Answer: D

Rationale: The correct answer is D: Color of the reactants. The color of the reactants does not affect the reaction rate as it is a purely visual characteristic and does not influence the speed at which the reaction occurs. Temperature affects reaction rate by providing energy for molecules to react faster. Surface area influences reaction rate by increasing the area of contact between reactants. Concentration of reactants affects reaction rate by increasing the frequency of collisions between molecules. In summary, factors like temperature, surface area, and concentration directly impact reaction rate, whereas color is merely a visual property and does not play a role in determining the speed of a chemical reaction.