Nursing Elites

1. In the reaction 2H2 + O2 → 2H2O, how many moles of oxygen are required to react completely with 4 moles of hydrogen?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The balanced chemical equation indicates that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O. To determine how many moles of O2 are required to react with 4 moles of H2, you can use the mole ratio from the balanced equation: 2 moles of H2 react with 1 mole of O2. Therefore, to react completely with 4 moles of H2, you would need 2 moles of O2 (4 moles H2 ÷ 2 moles H2 per 1 mole O2). Hence, 2 moles of oxygen are required to react completely with 4 moles of hydrogen. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as defined by the balanced chemical equation.

2. On a highway map, the scale indicates that 1 inch represents 45 miles. If the distance on the map is 3.2 inches, how far is the actual distance in miles?

• A. 144 miles
• B. 160 miles
• C. 180 miles
• D. 200 miles

Correct answer: A

Rationale: To find the actual distance in miles, you need to set up a proportion using the scale provided (1 inch = 45 miles). Since the distance on the map is 3.2 inches, you can set up the proportion: 1 inch / 45 miles = 3.2 inches / x miles. Cross-multiply to solve for x: 1 * x = 45 * 3.2, x = 144. Therefore, the actual distance in miles is 144. Choices B, C, and D are incorrect because they do not accurately calculate the actual distance using the scale provided.

3. How does the Pauli exclusion principle relate to the structure of the atom?

• A. It defines the maximum number of electrons allowed in each energy level.
• B. It explains why oppositely charged particles attract each other.
• C. It describes the wave-particle duality of electrons.
• D. It determines the arrangement of protons and neutrons in the nucleus.

Correct answer: A

Rationale: The Pauli exclusion principle states that no two electrons in an atom can have the same set of quantum numbers. This principle directly influences the structure of the atom by defining the maximum number of electrons allowed in each energy level. As a result, it helps determine the electron configuration and the arrangement of electrons in different orbitals within an atom. Choices B, C, and D are incorrect as they do not directly relate to the Pauli exclusion principle's specific impact on the electron distribution within an atom.

4. What is the balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride?

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: B

Rationale: In a balanced chemical equation, the number of atoms of each element must be the same on both sides of the equation. When sodium (Na) reacts with chlorine (Cl2) to form sodium chloride (NaCl), we need to ensure the equation is balanced. There are 2 chlorine atoms in Cl2; hence, we need 2 sodium atoms on the left side to balance it. Therefore, the balanced chemical equation is 2Na + Cl2 -> 2NaCl. Choice A is incorrect because it does not have the correct coefficients to balance the equation. Choice C is incorrect as it incorrectly represents the formula of sodium. Choice D is incorrect as it forms NaCl2, which is not the correct compound formed in this reaction.

5. The force applied is directly proportional to the stretch of a coil. If a force of 132 Newtons stretches a coil 0.07 meters, what force would be needed to stretch a coil 0.1 meter? Round your answer to the nearest tenth.

• A. 92.4 Newtons
• B. 1885.7 Newtons
• C. 188.6 Newtons
• D. 136.0 Newtons

Correct answer: C

Rationale: To find the force needed to stretch the coil 0.1 meters, we can set up a proportion based on the given information. The initial force and stretch are in direct proportion, so we can use this relationship to determine the unknown force. (132 N / 0.07 m) = X / 0.1 m. Cross-multiplying, we get 132 N * 0.1 m / 0.07 m = 188.57 N, which rounds to 188.6 N. Therefore, the correct answer is 188.6 Newtons. Choice A is incorrect as it does not match the calculated answer. Choice B is significantly higher and does not align with the proportional relationship. Choice D is close but does not account for the correct rounding as specified in the question.

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