Nursing Elites

1. What is the oxidation state of the potassium ion in the compound KCl?

• A. +1
• B. -1
• C. +2
• D. -2

Correct answer: A

Rationale: In the compound KCl (potassium chloride), potassium is in Group 1 of the periodic table, which means it has a valence electron of 1. Chlorine is in Group 17 and gains one electron to achieve a stable electron configuration by forming an ionic bond with potassium. As a result, the potassium ion in KCl has a +1 oxidation state. Therefore, the correct answer is +1. Choices B, C, and D are incorrect as they do not reflect the oxidation state of the potassium ion in KCl.

2. What is the oxidation state of the sulfur atom in sulfuric acid H2SO4?

• A. 4
• B. 6
• C. 8
• D. 10

Correct answer: B

Rationale: In sulfuric acid (H2SO4), sulfur has an oxidation state of +6. The oxidation state is determined by considering the overall charge of the compound and the known oxidation states of other elements. In this case, hydrogen is typically +1, and oxygen is -2. To balance the charges and match the compound's overall charge of 0, sulfur must have an oxidation state of +6. Choice A (4) is incorrect because it doesn't balance the charges in the compound. Choices C (8) and D (10) are also incorrect as they are not valid oxidation states for sulfur in this compound.

3. Which of the following types of matter changes in volume with changes in temperature and pressure?

• A. Liquid
• B. Gas
• C. Solid
• D. Plasma

Correct answer: B

Rationale: A gas changes its volume with changes in temperature and pressure due to the particles moving more rapidly at higher temperatures, and pressure affects the space between particles. Liquids have a relatively fixed volume but take the shape of their container. Solids have a definite shape and volume, so they do not change volume with changes in temperature and pressure. Plasma is a state of matter where particles are highly energized and do not have a fixed volume, but it does not exhibit volume changes with temperature and pressure variations.

4. What is the correct electron configuration for lithium?

• A. 1s²2s¹
• B. 1s²2s²
• C. 1s²2s¹2p¹
• D. 1s¹2s¹2p²

Correct answer: A

Rationale: The electron configuration for lithium is 1s²2s¹. Lithium has 3 electrons, and the configuration indicates that the first two electrons fill the 1s orbital, while the third electron fills the 2s orbital. Therefore, the correct electron configuration for lithium is 1s²2s¹. Choice B (1s²2s²) is incorrect as it represents the electron configuration for beryllium, not lithium. Choice C (1s²2s¹2p¹) includes the 2p orbital, which is not involved in lithium's electron configuration. Choice D (1s¹2s¹2p²) is incorrect as it does not accurately represent lithium's electron configuration.

5. What is the name of the compound CH₃-CH₂-CH₂-CH₃?

• A. Cyclobutane
• B. Butane
• C. Butene
• D. Butyne

Correct answer: B

Rationale: The compound CH₃-CH₂-CH₂-CH₃ is named butane. Butane is a straight-chain alkane comprising four carbon atoms connected by single bonds. The prefix 'but-' denotes the presence of four carbon atoms, while the suffix '-ane' indicates it is an alkane with single bonds between the carbon atoms. Choice A, Cyclobutane, is incorrect as it refers to a cyclic hydrocarbon with four carbon atoms in a ring structure. Choice C, Butene, is incorrect because it is an alkene with a double bond between two carbon atoms, not a saturated hydrocarbon like butane. Choice D, Butyne, is also incorrect as it is an alkyne with a triple bond between two carbon atoms, unlike the single bonds in butane.

Similar Questions