HESI A2
Chemistry Hesi A2
1. What is the correct formula for sodium nitrate?
- A. NaNO
- B. Na NO
- C. NaNO₃
- D. Na NO₂
Correct answer: C
Rationale: The correct formula for sodium nitrate is NaNO₃. In this formula, 'Na' represents sodium, 'N' represents nitrogen, and 'O₃' represents three oxygen atoms. Sodium nitrate consists of one sodium ion (Na⁺) and one nitrate ion (NO₃⁻), which means the correct formula is NaNO₃. Choice A (NaNO) is incorrect as it lacks the subscript indicating the presence of three oxygen atoms. Choice B (Na NO) is incorrect as it includes a space between 'Na' and 'NO', which is not part of the standard chemical formula notation. Choice D (Na NO₂) is incorrect as it indicates a different compound with a nitrite ion (NO₂⁻) instead of nitrate ion.
2. What is the normal body temperature in °C?
- A. 36°C
- B. 37°C
- C. 35°C
- D. 40°C
Correct answer: B
Rationale: The normal body temperature for humans is 37°C. This temperature is considered average and is a standard reference point for assessing an individual's health status. It is essential for the body to maintain this temperature to ensure optimal functioning of various physiological processes. Choice A (36°C) is incorrect as it is slightly below the normal body temperature. Choice C (35°C) is also incorrect as it is significantly lower than the normal body temperature. Choice D (40°C) is incorrect as it is significantly higher than the normal body temperature and would indicate a fever or other health issue.
3. Which branch of chemistry deals with the quantities and numeric relationships between compounds in a chemical reaction?
- A. Stoichiometry
- B. Molecular chemistry
- C. Atomic chemistry
- D. Thermodynamics
Correct answer: A
Rationale: Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It involves the calculation of quantities of substances consumed and produced in a chemical reaction based on the balanced chemical equation. Choice B, 'Molecular chemistry,' is incorrect as it focuses on the structure, properties, and reactions of molecules. Choice C, 'Atomic chemistry,' is incorrect as it primarily deals with the study of atoms and their interactions. Choice D, 'Thermodynamics,' is incorrect as it pertains to the study of energy and heat transfer in chemical and physical processes.
4. 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.
5. Which gas is produced when an acid reacts with a carbonate?
- A. Carbon dioxide
- B. Oxygen
- C. Hydrogen
- D. Nitrogen
Correct answer: A
Rationale: When an acid reacts with a carbonate, the chemical reaction typically yields carbon dioxide gas. Carbon dioxide is formed due to the chemical reaction between the acid and the carbonate, releasing this gas as a product. Therefore, the correct answer is 'Carbon dioxide.' Choices B, C, and D are incorrect as oxygen, hydrogen, and nitrogen are not the gases produced in this specific acid-carbonate reaction.
Similar Questions
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