Chemistry HESI A2 Practice Test

Correct Answer: C

Rationale: The correct answer is C: 11. Alkali metals are found in Group 1 of the periodic table, which includes elements like sodium (Na) and potassium (K). These elements have 11 protons in their atomic nucleus, giving them an atomic number of 11. The number of protons determines the element's identity, so alkali metals always have 11 protons. Choices A, B, and D are incorrect as they do not correspond to the characteristic number of protons for alkali metals.

Correct Answer: C

Rationale: To calculate molarity, we need to find the number of moles of solute (glucose) and the volume of the solution. 1. Calculate moles of glucose: 5g / 180 g/mol = 0.0278 mol 2. Calculate total mass of the solution: 5g (glucose) + 100g (water) = 105g 3. Calculate molarity: 0.0278 mol / 0.105 kg = 0.2667 M ≈ 2.8M (Choice C) Rationale: Molarity is moles of solute per liter of solution. The correct answer is C because it correctly calculates the molarity of the solution. Other choices are incorrect as they do not provide the accurate molarity value based on the given information.

Correct Answer: D

Rationale: The correct answer is D: Xe. Xenon (Xe) is a noble gas, meaning it has a full outer electron shell, making it highly stable and least likely to react with other elements. Li (A) is a highly reactive alkali metal, Cr (B) is a transition metal with varying reactivities, and Nd (C) is a rare-earth metal that can exhibit reactivity. In summary, Xe is the least reactive as noble gases tend to be chemically inert due to their stable electron configuration.

Correct Answer: D

Rationale: The correct name of AgNO₃ is Silver nitrate (D) because it follows the naming conventions for ionic compounds. "Silver" is the cation (Ag⁺) and "nitrate" is the anion (NO₃⁻), so the compound is named as "Silver nitrate." A: Argent nitrous - Incorrect, "argent" refers to silver but "nitrous" is incorrect for the nitrate ion. B: Argent oxide - Incorrect, "oxide" refers to O²⁻ ion, not NO₃⁻. C: Silver nitrite - Incorrect, "nitrite" is different from "nitrate," so the name is incorrect.

Correct Answer: C

Rationale: The correct answer is C: 11. Alkali metals are found in Group 1 of the periodic table, which includes elements like sodium (Na) and potassium (K). These elements have 11 protons in their atomic nucleus, giving them an atomic number of 11. The number of protons determines the element's identity, so alkali metals always have 11 protons. Choices A, B, and D are incorrect as they do not correspond to the characteristic number of protons for alkali metals.