Nursing Elites

1. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: A

Rationale: In the given reaction, the complete ionic equation is: 2H+(aq) + 2Cl-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + Ba2+(aq) + 2Cl-(aq). Spectator ions (Ba2+ and Cl-) do not participate in the net ionic equation, which simplifies to: 2H+(aq) + 2OH-(aq) → 2H2O(l). This equation represents the significant species involved in the reaction, showcasing the formation of water from the combination of hydrogen ions and hydroxide ions, resulting in the production of water molecules.

2. An element with atomic number 26 and mass number 56 is most likely to be:

• A. Iron (Fe)
• B. Cobalt (Co)
• C. Nickel (Ni)
• D. Manganese (Mn)

Correct answer: A

Rationale: The element with atomic number 26 and mass number 56 corresponds to Iron (Fe). Iron has 26 protons, which aligns with the given atomic number, and Fe-56 has 26 neutrons, which aligns with the given mass number. This confirms that Iron (Fe) is the correct answer. Cobalt (Co), Nickel (Ni), and Manganese (Mn) have different atomic numbers and mass numbers, so they are not the correct choices in this scenario.

3. A rocket engine expels hot gases backwards. What principle explains the rocket's forward motion?

• A. Newton's first law of motion
• B. Newton's second law of motion
• C. Newton's third law of motion
• D. Law of conservation of energy

Correct answer: C

Rationale: Newton's third law of motion states that for every action, there is an equal and opposite reaction. In the case of a rocket engine expelling hot gases backwards, the action is the expulsion of gases, and the reaction is the forward motion of the rocket. The hot gases being expelled act as the action force, propelling the rocket in the opposite direction as the reaction force, resulting in the rocket's forward motion. Newton's first law of motion (Choice A) pertains to inertia, stating that an object in motion will stay in motion unless acted upon by an external force. Newton's second law of motion (Choice B) relates force, mass, and acceleration, which is not directly applicable to the scenario of a rocket engine propulsion. The law of conservation of energy (Choice D) is a fundamental principle stating that energy cannot be created or destroyed but can only be transformed, which does not directly explain the forward motion of the rocket in this context.

4. Which term refers to a position farther from the midline of the body? For example, the little toe is lateral to the big toe on the same foot.

• A. Lateral
• B. Medial
• C. Proximal
• D. Distal

Correct answer: A

Rationale: The correct answer is A: Lateral. Lateral refers to a position farther away from the midline of the body. In the example provided, the little toe is indeed lateral to the big toe on the same foot. This is in contrast to 'medial,' which means closer to the midline. 'Proximal' refers to a position closer to the point of attachment or the trunk of the body, while 'distal' refers to a position farther from the point of attachment or the trunk of the body.

5. Which of the following is NOT a property of a catalyst?

• A. Increases the rate of a reaction
• B. Remains unchanged after the reaction
• C. Lowers the activation energy
• D. Creates new products

Correct answer: D

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It remains unchanged after the reaction, which eliminates option B. A catalyst works by lowering the activation energy required for the reaction to occur, which eliminates option C. A catalyst does not create new products in a reaction; it only facilitates the conversion of reactants into products more efficiently. Therefore, option D is NOT a property of a catalyst.

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