what is the oxidation state of oxygen in most compounds
Logo

Nursing Elites

HESI A2

HESI A2 Chemistry Practice Test

1. What is the typical oxidation state of oxygen in most compounds?

Correct answer: B

Rationale: The correct answer is B: "-2". Oxygen usually exhibits an oxidation state of -2 in most compounds. This is due to oxygen's high electronegativity, which causes it to attract electrons, leading to the gain of two electrons in chemical reactions. Choice A (-1) is incorrect because oxygen rarely has an oxidation state of -1 in compounds. Choice C (0) is incorrect as oxygen does not usually have an oxidation state of zero in compounds. Choice D (-3) is incorrect as oxygen does not commonly have an oxidation state of -3 in compounds.

2. What is the pH of a neutral solution?

Correct answer: A

Rationale: The correct answer is A: 7. A neutral solution has a pH of 7. In the pH scale, values below 7 are acidic, 7 is neutral, and values above 7 are basic. Therefore, a solution with a pH of 7 is considered neutral as it is neither acidic nor basic. Choices B, C, and D are incorrect because a pH of 0 indicates a strong acid, a pH of 14 indicates a strong base, and a pH of 4 indicates an acidic solution. None of these values represent a neutral solution.

3. What are bases or alkaline solutions known as?

Correct answer: A

Rationale: Bases or alkaline solutions are known as 'hydrogen acceptors.' They accept protons (H+) in chemical reactions, as opposed to acids that donate protons. This property allows bases to neutralize acids and form salts. Choice B, 'Solutions of low pH,' is incorrect because bases have high pH values, not low. Choice C, 'Hydrogen donors,' is incorrect as bases do not donate protons but accept them. Choice D, 'Amphoteric,' refers to substances that can act as both acids and bases, which is not the definition of bases. Therefore, the correct answer is A.

4. Which of the following is a property of an acid?

Correct answer: C

Rationale: The correct property of an acid is that it 'reacts with bases.' Acids are known for their ability to react with bases to form salts and water through a process called neutralization. This unique reaction distinguishes acids from other substances and is a fundamental characteristic of acids in chemistry. Choices A, B, and D are incorrect. Acids do not have a bitter taste (Choice A), a slippery feel (Choice B), or a sweet taste (Choice D). These properties are not typical of acids and may lead to confusion if associated with acids.

5. What type of chemical reaction is represented by AB → A + B?

Correct answer: B

Rationale: The chemical equation AB → A + B represents a decomposition reaction. In a decomposition reaction, a single compound breaks down into two or more simpler substances. In this specific reaction, compound AB is decomposed into its elements, A and B, making it a decomposition reaction. Choice A, Synthesis, involves the combination of two or more substances to form a more complex product, which is not the case here. Choices C and D, Single replacement and Double replacement, involve the exchange of ions between compounds or elements, which is not happening in the given reaction.

Similar Questions

If electrons are not shared equally in a covalent bond, the bond is what?
How much concentrated HCl should be used to prepare 500 mL of a 0.100 M HCl solution?
Which of these types of intermolecular force is the strongest?
What defines a balanced chemical equation?
Which type of chemical reaction involves two ionic compounds where the reactants yield 'switched partners'?

Access More Features

HESI A2 Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

HESI A2 Premium
$149.99/ 90 days

  • Actual HESI A2 Questions
  • 3,000 questions with answers
  • 90 days access

Other Courses