Nursing Elites

1. To the nearest whole number, what is the mass of one mole of water?

• A. 16 g/mol
• B. 18 g/mol
• C. 20 g/mol
• D. 22 g/mol

Correct answer: B

Rationale: The molar mass of water (H₂O) is calculated by adding the atomic masses of two hydrogen atoms (each with a molar mass of approximately 1 g/mol) and one oxygen atom (with a molar mass of approximately 16 g/mol). Therefore, the molar mass of water is approximately 18 g/mol, making choice B the correct answer. Choice A (16 g/mol) is incorrect because it represents the molar mass of oxygen, not water. Choices C (20 g/mol) and D (22 g/mol) are incorrect as they do not correspond to the molar mass of water.

2. Which is a triatomic allotrope of oxygen?

• A. Ozone
• B. Water
• C. Acidic oxide
• D. Carbon dioxide

Correct answer: A

Rationale: Ozone (O3) is a triatomic allotrope of oxygen. It differs from the common diatomic oxygen molecule (O2) by having three oxygen atoms bonded together. Ozone is known for its protective role in the Earth's atmosphere, absorbing most of the Sun's harmful ultraviolet radiation. Water (H2O) is a compound composed of two hydrogen atoms and one oxygen atom. Acidic oxide and carbon dioxide are not triatomic allotropes of oxygen. Carbon dioxide consists of one carbon atom and two oxygen atoms, while acidic oxides refer to compounds where oxygen is bonded with other elements to form oxides, and they are not allotropes of oxygen.

3. Which substance has a pH value greater than 7?

• A. Water
• B. Vinegar
• C. Lemon juice
• D. Baking soda

Correct answer: D

Rationale: The correct answer is D, Baking soda. Baking soda has a pH greater than 7, making it basic. pH values above 7 indicate alkalinity, and baking soda, being a base, has a pH higher than 7. Water, vinegar, and lemon juice have pH values below 7, indicating acidity. Water is neutral with a pH of 7, while vinegar and lemon juice are acidic with pH values lower than 7.

4. To the nearest whole number, what is the mass of one mole of hydrogen iodide?

• A. 2 g/mol
• B. 58 g/mol
• C. 87 g/mol
• D. 128 g/mol

Correct answer: C

Rationale: The molar mass of hydrogen iodide (HI) is the sum of the atomic masses of its constituent elements. Hydrogen (H) has a molar mass of approximately 1 g/mol, and iodine (I) has a molar mass of about 127 g/mol. Thus, the molar mass of hydrogen iodide (HI) is approximately 1 + 127 = 128 g/mol. Rounding to the nearest whole number, the molar mass of hydrogen iodide is 128 g/mol, which is closest to choice C. Choice A (2 g/mol) is too low and does not reflect the correct molar mass of hydrogen iodide. Choice B (58 g/mol) is significantly lower than the actual molar mass. Choice D (128 g/mol) matches the calculated molar mass but is not the nearest whole number as requested.

5. What is the correct name of AgNO₃?

• A. Argent nitrous
• B. Argent oxide
• C. Silver nitrite
• D. Silver nitrate

Correct answer: D

Rationale: The correct name for AgNO₃ is silver nitrate. In chemical nomenclature, the element symbol Ag represents silver, and the polyatomic ion NO₃ is known as nitrate. Therefore, when the silver ion (Ag⁺) combines with the nitrate ion (NO₃⁻), the resulting compound is named silver nitrate (AgNO₃). Choices A, B, and C are incorrect because they do not accurately represent the composition of AgNO₃. Argent nitrous (Choice A) and Argent oxide (Choice B) do not reflect the correct anion, and Silver nitrite (Choice C) uses a different anion altogether.

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