Nursing Elites

1. How many electrons are shared in a single covalent bond?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The correct answer is B: '2'. In a single covalent bond, two electrons are shared between two atoms. Each atom contributes one electron to form the bond, resulting in the sharing of a total of two electrons. Choice A is incorrect because a single covalent bond involves the sharing of two electrons, not one. Choices C and D are incorrect as they do not represent the correct number of electrons shared in a single covalent bond.

2. What is stoichiometry?

• A. The study of energy changes in chemical reactions
• B. The study of the mass relationships in chemical reactions
• C. The study of atomic structure
• D. The study of molecular geometry

Correct answer: B

Rationale: Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It focuses on the calculation of the amounts of substances consumed and produced in a reaction based on the balanced chemical equation. Choice A is incorrect because the study of energy changes in chemical reactions falls under thermodynamics. Choice C is incorrect as atomic structure is related to the arrangement of atoms within molecules. Choice D is incorrect as molecular geometry deals with the spatial arrangement of atoms within molecules.

3. The molar mass of glucose is 180 g/mol. If an IV solution contains 5 g of glucose in 100 g of water, what is the molarity of the solution?

• A. 0.28M
• B. 1.8M
• C. 2.8M
• D. 18M

Correct answer: C

Rationale: To calculate the molarity of the solution, we first need to determine the moles of solute (glucose) and solvent (water) separately. The molar mass of glucose is 180 g/mol. First, calculate the moles of glucose: 5 g / 180 g/mol = 0.02778 mol of glucose. Next, calculate the moles of water: 100 g / 18 g/mol = 5.56 mol of water. Now, calculate the total moles in the solution: 0.02778 mol glucose + 5.56 mol water = 5.5878 mol. Finally, calculate the molarity: Molarity = moles of solute / liters of solution. Since the total mass of the solution is 100 g + 5 g = 105 g = 0.105 kg, which is equal to 0.105 L, the molarity is 5.5878 mol / 0.105 L = 53.22 M, which rounds to 2.8M. Therefore, the correct answer is 2.8M. Choices A, B, and D are incorrect because they do not reflect the accurate molarity calculation based on the moles of solute and volume of the solution.

4. In the periodic table, which group contains the alkali metals?

• A. Group 7
• B. Group 1
• C. Group 2
• D. Group 3

Correct answer: B

Rationale: The correct answer is Group 1. Alkali metals are found in Group 1 of the periodic table, which includes elements such as lithium, sodium, and potassium. These elements are known for their high reactivity and tendency to form alkaline solutions when they react with water. Therefore, Group 1 is specifically designated as the group containing alkali metals. Choice A (Group 7) is incorrect as Group 7 contains the halogens. Choice C (Group 2) is incorrect as Group 2 contains the alkaline earth metals. Choice D (Group 3) is incorrect as Group 3 contains the scandium group of elements.

5. Which elements are typically involved in hydrogen bonding?

• A. Carbon, hydrogen, oxygen
• B. Fluorine, chlorine, oxygen
• C. Fluorine, chlorine, nitrogen
• D. Fluorine, oxygen, nitrogen

Correct answer: D

Rationale: Hydrogen bonding occurs between hydrogen and highly electronegative atoms such as fluorine, oxygen, and nitrogen. These atoms have a strong pull on the shared electrons, leading to a partial negative charge on them, which allows them to form hydrogen bonds with hydrogen or other electronegative atoms. Choice A is incorrect because carbon is not typically involved in hydrogen bonding. Choice B is incorrect because chlorine is not as electronegative as nitrogen, and choice C is incorrect because nitrogen is more electronegative than chlorine.

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