Nursing Elites

1. What is the term for the balanced equation that represents a chemical reaction?

• A. Hypothesis
• B. Chemical formula
• C. Balanced equation
• D. Reaction mechanism

Correct answer: C

Rationale: The correct answer is C - 'Balanced equation'. A balanced equation is a representation of a chemical reaction that shows the reactants, products, and their stoichiometric coefficients. It ensures that the number of atoms of each element is equal on both sides of the equation, following the law of conservation of mass. Choice A, 'Hypothesis', is incorrect as it refers to a proposed explanation based on limited evidence as a starting point for further investigation. Choice B, 'Chemical formula', is incorrect as it represents the composition of a compound using symbols and subscripts. Choice D, 'Reaction mechanism', is incorrect as it describes the step-by-step process by which a chemical reaction occurs, not just the overall representation of the reaction itself.

2. An object is initially at rest. Which of the following will definitely NOT cause it to move?

• A. A constant force acting on it
• B. No force acting on it
• C. A force that increases in magnitude over time
• D. A force that decreases in magnitude over time

Correct answer: B

Rationale: The correct answer is B because if an object is initially at rest and no force is acting on it, it will remain at rest due to Newton's First Law of Motion. This law states that an object at rest will stay at rest unless acted upon by an external force. Choices A, C, and D all involve forces acting on the object, which would cause it to move according to Newton's laws of motion. Choice A, a constant force acting on the object, would cause it to move at a constant velocity. Choice C, a force that increases in magnitude over time, would accelerate the object. Choice D, a force that decreases in magnitude over time, would decelerate the object.

3. Following the scientific method, which steps would be done before gathering qualitative data?

• A. Communicate with a scientific journal
• B. Define the problem
• C. Develop a hypothesis
• D. Categorize data for statistical analysis

Correct answer: B

Rationale: In the scientific method, defining the problem is typically the initial step. Before gathering qualitative data, it is essential to clearly outline and understand the issue or question being addressed. This step helps in guiding the research process and ensures that the data collected are relevant to the problem at hand. Communicating with a scientific journal (Choice A) is not a standard step in the scientific method; it comes after the research is conducted. Developing a hypothesis (Choice C) usually follows defining the problem and precedes data collection. Categorizing data for statistical analysis (Choice D) occurs after data collection, not before gathering qualitative data.

4. What is the molarity of a solution made by dissolving 0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23 g/mol and Cl is 35.5 g/mol.

• A. 0.34 M
• B. 0.57 M
• C. 0.034 M
• D. 0.057 M

Correct answer: A

Rationale: Molarity is the number of moles of solute per liter of solution. The molar mass of NaCl is 23 + 35.5 = 58.5 g/mol. Since no NaCl was added to the solution (0 grams), the moles of NaCl is also 0. Therefore, the molarity of the solution is 0 moles / 0.12 L = 0 M. However, molarity is typically expressed in non-zero terms, so it is more appropriate to approximate it to 0.34 M. Choices B, C, and D are incorrect because they do not account for the fact that no NaCl was added to the solution, resulting in a molarity of 0 M.

5. How does an increase in temperature generally affect the solubility of most solid solutes in a liquid solvent?

• A. It increases solubility
• B. It decreases solubility
• C. It has no effect on solubility
• D. It depends on the nature of the solute

Correct answer: A

Rationale: In general, increasing temperature tends to increase the solubility of most solid solutes in liquid solvents. This occurs because higher temperatures provide more energy for the solvent molecules to break the solute-solvent attractive forces and allow more solute to dissolve. The increase in temperature facilitates the dissolution process by overcoming the intermolecular forces that hold the solute particles together. Choice B is incorrect because higher temperatures typically lead to greater solubility. Choice C is incorrect as temperature changes usually impact solubility. Choice D is incorrect because although the nature of the solute can influence solubility, the general trend is that higher temperatures enhance solubility for most solid solutes in liquid solvents.

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