Nursing Elites

1. What type of reaction occurs when an acid and a base react to form water and salt?

• A. Neutralization reaction
• B. Decomposition reaction
• C. Combustion reaction
• D. Redox reaction

Correct answer: A

Rationale: A neutralization reaction is the correct answer. In this type of reaction, an acid and a base combine to form water and salt. The acid donates a proton (H+) to the base, forming water, while the remaining ions combine to form a salt. This reaction results in the neutralization of both the acid and the base, hence the name 'neutralization reaction.' Choice B, decomposition reaction, is incorrect because it refers to a reaction where a compound breaks down into simpler substances. Choice C, combustion reaction, is incorrect as it involves a substance reacting with oxygen to produce heat and light. Choice D, redox reaction, is incorrect because it involves the transfer of electrons between reactants.

2. To the nearest whole number, what is the mass of one mole of hydrogen chloride?

• A. 36 g/mol
• B. 38 g/mol
• C. 71 g/mol
• D. 74 g/mol

Correct answer: C

Rationale: The molar mass of hydrogen chloride (HCl) is calculated by adding the atomic masses of hydrogen (H) and chlorine (Cl) together. The atomic mass of hydrogen is approximately 1 g/mol, and the atomic mass of chlorine is approximately 35.5 g/mol. Therefore, the molar mass of hydrogen chloride (HCl) is approximately 1 + 35.5 = 36.5 g/mol. When rounded to the nearest whole number, it is 36 g/mol. Therefore, the correct answer is 36 g/mol. Choices A, B, and D are incorrect as they do not reflect the accurate molar mass of hydrogen chloride.

3. Which law states that matter can neither be created nor destroyed during a chemical reaction?

• A. Law of Conservation of Energy
• B. Law of Conservation of Mass
• C. Law of Constant Composition
• D. Law of Multiple Proportions

Correct answer: B

Rationale: The correct answer is B, the Law of Conservation of Mass. This law, formulated by Antoine Lavoisier, states that matter cannot be created or destroyed in a chemical reaction. It is a fundamental principle in chemistry that explains the preservation of mass during chemical reactions, indicating that the total mass of the reactants is equal to the total mass of the products. The other choices are incorrect because: A: The Law of Conservation of Energy states that energy cannot be created or destroyed, not matter. C: The Law of Constant Composition refers to compounds having the same composition by mass regardless of their source or how they were prepared, not about the conservation of matter in reactions. D: The Law of Multiple Proportions describes the ratios in which elements combine to form compounds, not the conservation of mass.

4. Which of the following represents a hydride ion?

• A. H⁻
• B. H⁺
• C. OH⁻
• D. HCl

Correct answer: A

Rationale: The hydride ion is denoted by H⁻, indicating that it has gained an extra electron to complete its valence shell, resulting in a full octet and a net charge of -1. This ion is commonly found in metal hydrides and plays a significant role in various chemical reactions. Option B, H⁺, represents a proton with a positive charge. Option C, OH⁻, represents the hydroxide ion, consisting of oxygen and hydrogen. Option D, HCl, is a compound composed of hydrogen and chlorine ions, not a hydride ion.

5. Which number represents the number of protons in an element?

• A. Atomic mass
• B. Mass number
• C. Atomic number
• D. Proton number

Correct answer: C

Rationale: The correct answer is C: Atomic number. The atomic number corresponds to the number of protons in an element. Protons are positively charged subatomic particles found in the nucleus of an atom. Each element has a unique atomic number, which defines its identity based on the number of protons it contains. Choice A, Atomic mass, is incorrect as it refers to the average mass of an atom of an element. Choice B, Mass number, represents the total number of protons and neutrons in an atom's nucleus. Choice D, Proton number, is not a commonly used term in chemistry to indicate the number of protons.

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