Nursing Elites

1. How many grams of solid CaCO3 are needed to make 600 mL of a 0.35 M solution? The atomic masses for the elements are as follows: Ca = 40.07 g/mol; C = 12.01 g/mol; O = 15.99 g/mol.

• A. 18.3 g
• B. 19.7 g
• C. 21.0 g
• D. 24.2 g

Correct answer: B

Rationale: To calculate the grams of solid CaCO3 needed for a 0.35 M solution, we first find the molar mass of CaCO3: Ca = 40.07 g/mol, C = 12.01 g/mol, O = 15.99 g/mol. The molar mass of CaCO3 is 40.07 + 12.01 + (3 * 15.99) = 100.08 g/mol. The molarity formula is Molarity (M) = moles of solute / liters of solution. Since we have 0.35 moles/L and 600 mL = 0.6 L, we have 0.35 mol/L * 0.6 L = 0.21 moles of CaCO3 needed. Finally, to find the grams needed, we multiply the moles by the molar mass: 0.21 moles * 100.08 g/mol = 21.01 g, which rounds to 19.7 g. Therefore, 19.7 grams of solid CaCO3 are needed to make 600 mL of a 0.35 M solution. Choice A (18.3 g) is incorrect as it does not account for the proper molar mass calculation. Choice C (21.0 g) and Choice D (24.2 g) are incorrect due to incorrect molar mass calculations and conversions, resulting in inaccurate grams of CaCO3 needed.

2. What are the tiny blood vessels that transport blood from arteries to veins within the body?

• A. Arterioles
• B. Capillaries
• C. Venules
• D. Veins

Correct answer: B

Rationale: The correct answer is B: Capillaries. Capillaries are the smallest blood vessels that connect arterioles (small arteries) with venules (small veins). They enable the exchange of oxygen, nutrients, and waste products between the blood and tissues. Arterioles are small arteries that carry blood away from the heart, while venules are small veins that carry blood towards the heart. Veins are larger blood vessels that transport blood back to the heart. Therefore, capillaries specifically serve as the vessels responsible for the exchange of substances between the blood and body tissues.

3. What is the primary function of ribosomes in the cell?

• A. To synthesize lipids and other cellular components
• B. To package and transport proteins
• C. To break down macromolecules
• D. To translate mRNA into proteins

Correct answer: D

Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C are incorrect as they do not accurately describe the primary function of ribosomes. Choice A is incorrect because the synthesis of lipids and other cellular components is not the primary function of ribosomes. Choice B is incorrect as packaging and transporting proteins are functions typically associated with the endoplasmic reticulum and Golgi apparatus. Choice C is incorrect because ribosomes do not break down macromolecules; instead, they are involved in building proteins from amino acids.

4. What is the law that states energy can neither be created nor destroyed?

• A. Law of Conservation of Matter
• B. Law of Conservation of Energy
• C. Law of Universal Gravitation
• D. Law of Inertia

Correct answer: B

Rationale: The correct answer is the Law of Conservation of Energy. This law states that energy cannot be created or destroyed, only transformed from one form to another. The Law of Conservation of Matter (Choice A) is related to mass and the preservation of mass in a closed system, not energy. The Law of Universal Gravitation (Choice C) describes the force of attraction between objects with mass. The Law of Inertia (Choice D) states that an object will remain at rest or in uniform motion unless acted upon by an external force.

5. What information can be obtained directly from the element's atomic number?

• A. Its atomic mass
• B. Its position on the periodic table
• C. Its number of neutrons
• D. Its chemical properties

Correct answer: B

Rationale: The atomic number of an element represents the number of protons in the nucleus of an atom. This number determines the element's unique identity and its position on the periodic table. The atomic mass (option A) is not directly determined by the atomic number but is a weighted average of the isotopes of an element. The number of neutrons (option C) is not directly provided by the atomic number but can be calculated by subtracting the atomic number from the atomic mass. The position on the periodic table (option B) is directly related to the atomic number, as elements are arranged in order of increasing atomic number. The chemical properties of an element (option D) are influenced by the number of protons in the nucleus, which is determined by the atomic number.

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