Nursing Elites

1. How much concentrated HCl should be used to prepare 500 mL of a 0.100 M HCl solution?

• A. 75 mL
• B. 100 mL
• C. 125 mL
• D. 150 mL

Correct answer: B

Rationale: To prepare a 0.100 M HCl solution with a volume of 500 mL, you can use the formula C1V1 = C2V2, where C1 is the concentration of the concentrated HCl solution, V1 is the volume of concentrated HCl solution used, C2 is the desired concentration (0.100 M), and V2 is the final volume (500 mL). Rearranging the formula to solve for V1, you get V1 = (C2V2) / C1. Plugging in the values (0.100 M)(500 mL) / C1 = 100 mL, which means 100 mL of concentrated HCl should be used to prepare 500 mL of a 0.100 M HCl solution. Therefore, the correct answer is 100 mL. Choice A (75 mL), Choice C (125 mL), and Choice D (150 mL) are incorrect as they do not match the calculated volume needed to prepare the desired concentration of HCl solution.

2. What is the normal body temperature in Fahrenheit?

• A. 96°F
• B. 98.6°F
• C. 100°F
• D. 95°F

Correct answer: B

Rationale: The normal body temperature for humans is 98.6°F, which is equivalent to 37°C. This temperature is considered the average baseline for most individuals when measured orally. Choice A (96°F) is too low for normal body temperature. Choice C (100°F) is too high for normal body temperature. Choice D (95°F) is also lower than the normal body temperature range. Therefore, the correct answer is B, 98.6°F.

3. What is the chemical symbol for sodium?

• A. N
• B. Na
• C. Cl
• D. H

Correct answer: B

Rationale: The correct chemical symbol for sodium is 'Na.' In the periodic table, sodium is represented by the symbol 'Na,' derived from its Latin name 'natrium.' The symbol 'N' represents nitrogen, not sodium. 'Cl' is the symbol for chlorine, and 'H' is the symbol for hydrogen. Therefore, 'Na' is the correct chemical symbol for sodium.

4. What is the primary function of enzymes?

• A. To provide energy for reactions
• B. To speed up reactions
• C. To decrease activation energy
• D. To act as a catalyst

Correct answer: B

Rationale: Enzymes function to speed up reactions by lowering the activation energy required for the reaction to occur. They act as biological catalysts, providing an alternative pathway for the reaction to proceed more rapidly without being consumed in the process. Choices A, C, and D are incorrect because enzymes do not provide energy for reactions (they do not generate energy), their primary function is not to decrease activation energy (though they do lower it), and while they act as catalysts, the primary function is to speed up reactions by lowering activation energy.

5. What is the correct formula for calcium carbonate?

• A. CaSO₃
• B. CaCO₃
• C. Ca(OH)â‚‚
• D. CH₃OH

Correct answer: B

Rationale: The correct formula for calcium carbonate is CaCO₃, which consists of one calcium (Ca) atom, one carbon (C) atom, and three oxygen (O) atoms. Therefore, choice B, CaCO₃, is the accurate formula for calcium carbonate. Choices A, C, and D do not represent the correct formula for calcium carbonate. Choice A, CaSO₃, is calcium sulfite, not calcium carbonate. Choice C, Ca(OH)₂, is calcium hydroxide, and choice D, CH₃OH, is methanol, none of which are correct formulas for calcium carbonate.

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