Nursing Elites

1. What is the balanced chemical equation for the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH)?

• A. H2SO4 + KOH → K2SO4 + H2O
• B. 2H2SO4 + 2KOH → 2K2SO4 + 2H2O
• C. H2SO4 + 2KOH → K2SO4 + 2H2O
• D. H2SO4 + 2KOH → K2SO4 + H2O

Correct answer: C

Rationale: When sulfuric acid (H2SO4) reacts with potassium hydroxide (KOH), it forms potassium sulfate (K2SO4) and water (H2O). To balance the equation, 2 KOH molecules are required to react with 1 H2SO4 molecule, resulting in 1 K2SO4 molecule and 2 H2O molecules. Therefore, the balanced chemical equation is H2SO4 + 2KOH → K2SO4 + 2H2O, which corresponds to option C. Choice A is incorrect because it does not account for the correct stoichiometry between the reactants and products. Choice B incorrectly doubles all the molecules in the reaction, leading to an unbalanced equation. Choice D incorrectly balances the equation with 1 KOH molecule instead of the required 2 KOH molecules, making it unbalanced. Thus, option C is the correct balanced chemical equation for the reaction between sulfuric acid and potassium hydroxide.

2. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

• A. Frequency remains the same.
• B. Frequency is halved.
• C. Frequency is doubled.
• D. Frequency information is insufficient to determine.

Correct answer: B

Rationale: When the wavelength of a wave is doubled, and the speed of the wave remains constant, the frequency of the wave is halved. This relationship is governed by the equation speed = frequency x wavelength. Therefore, if the wavelength is doubled while the speed remains constant, the frequency must be halved to maintain a constant speed. Choice A is incorrect because frequency and wavelength are inversely proportional when speed is constant. Choice C is incorrect as doubling the wavelength does not result in a doubled frequency. Choice D is incorrect as the relationship between frequency, wavelength, and speed can be determined using the given information.

3. Identify the spectator ions in the reaction: 2KCl + Pb(NO3)2 → 2KNO3 + PbCl2.

• A. K+ and NO3-
• B. K+ and Cl-
• C. Pb2+ and NO3-
• D. Pb2+ and Cl-

Correct answer: B

Rationale: - In the reaction, potassium ions (K+) and chloride ions (Cl-) are present on both sides of the equation. They are not involved in the formation of the products and remain unchanged. - Lead ions (Pb2+) and nitrate ions (NO3-) are involved in the formation of the products potassium nitrate (KNO3) and lead(II) chloride (PbCl2). - Therefore, the spectator ions in this reaction are K+ and Cl-.

4. What does the term 'solute' refer to in a solution?

• A. The substance present in the largest amount
• B. The substance that dissolves in the solvent
• C. The liquid portion of the solution
• D. The temperature at which the solution freezes

Correct answer: B

Rationale: In a solution, the term 'solute' specifically refers to the substance that dissolves in the solvent to create a solution. The solute is typically present in a smaller amount compared to the solvent. Option B correctly identifies the solute as the substance that undergoes dissolution in the solvent, making it the correct choice. Choices A, C, and D are incorrect. Choice A is actually describing the solvent, which is the substance present in the largest amount in a solution. Choice C refers to the solvent, not the solute. Choice D is unrelated to the term 'solute' as it describes the colligative property of freezing point depression, not the solute itself.

5. When is work done by a force on an object?

• A. Only when the object moves in the direction of the force
• B. Only when the object moves against the force
• C. Only when the object moves vertically
• D. Only when the force is applied for a specific duration

Correct answer: A

Rationale: Work is done by a force on an object when the object moves in the direction of the force. This is because work is defined as the product of the force applied to an object and the distance over which the force is applied. When the object moves in the direction of the force, the force contributes to the displacement of the object, resulting in work being done. If the object moves perpendicular to the force, no work is done because the force does not contribute to the displacement. Moving against the force also results in work being done as the force is causing the displacement. The vertical movement of the object does not determine whether work is done; it is the alignment of the force with the object's displacement that matters. The duration of force application does not impact whether work is done; as long as the force causes the object to move in its direction, work is being done.

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