Nursing Elites

1. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

• A. Na
• B. H2O
• C. NaOH
• D. H2

Correct answer: A

Rationale: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.

2. What is the term for a solution with a pH value less than 7?

• A. Acidic
• B. Neutral
• C. Alkaline
• D. Basic

Correct answer: A

Rationale: Solutions with a pH less than 7 are classified as acidic. pH values below 7 indicate an acidic solution, which means it has a higher concentration of hydrogen ions. Choices B, C, and D are incorrect as they describe neutral (pH 7), alkaline (pH greater than 7), and basic (another term for alkaline), respectively, which are not applicable to solutions with a pH less than 7.

3. Which of the following is an example of a tissue?

• A. chloroplasts
• B. liver
• C. mammal
• D. hamstring

Correct answer: B

Rationale: The correct answer is 'B: liver.' The liver is an example of a tissue. Tissues are groups of cells that work together to perform specific functions in the body. The liver is made up of different types of cells that work together to carry out various essential functions, such as detoxification, metabolism, and storage of nutrients. Option A (chloroplasts) refers to organelles, not tissues. Option D (hamstring) is a muscle, not a tissue. Option C (mammal) represents a higher level of organization than tissues, as it refers to a classification of organisms, not a specific tissue type.

4. In a study where fish are fed different amounts of food daily for four weeks in separate tanks, with fish weight measured weekly, what is the dependent variable?

• A. Weight of the fish
• B. Type of food used
• C. Number of fish tanks
• D. Frequency of feedings

Correct answer: A

Rationale: The weight of the fish is the dependent variable in this study because it is the outcome being measured in response to the varying feeding amounts. The weight of the fish changes based on the feeding regimen, making it the dependent variable. The type of food used (choice B), number of fish tanks (choice C), and frequency of feedings (choice D) are not the dependent variables in this study. These factors may be independent variables that are manipulated or controlled in the experiment to observe their impact on the dependent variable, which is the weight of the fish.

5. Which of the following statements correctly describes the function of a physiological structure?

• A. The trachea connects the throat and the stomach.
• B. The esophagus joins the larynx with the lungs.
• C. The diaphragm controls the height of the thoracic cavity.
• D. The epiglottis covers the trachea during swallowing.

Correct answer: D

Rationale: The epiglottis is a flap of tissue that covers the trachea during swallowing to prevent food and liquids from entering the airway. This action helps direct food into the esophagus, ensuring proper passage into the digestive system and avoiding potential choking or aspiration into the lungs. Choices A, B, and C are incorrect because the trachea connects the larynx to the bronchi, the esophagus connects the throat to the stomach, and the diaphragm is a muscle that plays a vital role in breathing by separating the thoracic and abdominal cavities, aiding in respiration.

Similar Questions