HESI A2
HESI A2 Chemistry
1. To the nearest whole number, what is the mass of one mole of sodium chloride?
- A. 36 g/mol
- B. 43 g/mol
- C. 58 g/mol
- D. 72 g/mol
Correct answer: C
Rationale: The molar mass of sodium chloride (NaCl) is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of sodium is approximately 23 g/mol and chlorine is approximately 35.5 g/mol. Adding these two atomic masses gives us a molar mass of approximately 58 g/mol for sodium chloride (NaCl). Therefore, the correct answer is C, 58 g/mol. Choice A (36 g/mol) is incorrect as it does not account for the individual atomic masses of sodium and chlorine. Choice B (43 g/mol) and choice D (72 g/mol) are also incorrect as they do not reflect the accurate molar mass of sodium chloride.
2. What are proteins made up of?
- A. Fatty acids
- B. Amino acids
- C. Nucleotides
- D. Sugars
Correct answer: B
Rationale: Proteins are made up of amino acids. Amino acids are the building blocks of proteins, essential for various biological processes in the body such as enzyme function, transport, and structural support. Fatty acids (Choice A) are components of lipids, not proteins. Nucleotides (Choice C) are the building blocks of nucleic acids like DNA and RNA, not proteins. Sugars (Choice D) are carbohydrates and are not the primary components of proteins.
3. What type of reaction occurs when an acid and a base react to form water and salt?
- A. Neutralization reaction
- B. Decomposition reaction
- C. Combustion reaction
- D. Redox reaction
Correct answer: A
Rationale: A neutralization reaction is the correct answer. In this type of reaction, an acid and a base combine to form water and salt. The acid donates a proton (H+) to the base, forming water, while the remaining ions combine to form a salt. This reaction results in the neutralization of both the acid and the base, hence the name 'neutralization reaction.' Choice B, decomposition reaction, is incorrect because it refers to a reaction where a compound breaks down into simpler substances. Choice C, combustion reaction, is incorrect as it involves a substance reacting with oxygen to produce heat and light. Choice D, redox reaction, is incorrect because it involves the transfer of electrons between reactants.
4. 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.
5. Which of the following is not an allotrope of carbon?
- A. Diamond
- B. Graphite
- C. Fluorine
- D. Buckminsterfullerene
Correct answer: C
Rationale: The correct answer is C: Fluorine. Allotropes of carbon are different forms of the same element. Diamonds, graphite, and buckminsterfullerene are all allotropes of carbon. However, fluorine is a separate chemical element and not an allotrope of carbon. Therefore, fluorine does not belong to the group of carbon allotropes.
Similar Questions
Access More Features
HESI A2 Basic
$49/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access