CHEMISTRY HESI A2 ACTUAL EXAM 2026 | QUESTIONS AND CORRECT DETAILED CORRECT DETAILED100% ANSWERS WITH RATIONALE | ALREADY A GRADED | ALREADY

CHEMISTRY HESI A2 ACTUAL EXAM 2026 |
QUESTIONS AND CORRECT DETAILED
CORRECT DETAILED100% ANSWERS
WITH RATIONALE | ALREADY A GRADED |
ALREADY
A GRADED | PDF




1. Which of the following is a noble gas?
A) Oxygen
B) Neon
C) Nitrogen
D) Hydrogen

Correct detailed100% answer: B) Neon
Explanation: 👀 ** Noble gases are in Group 18 of the periodic
table and are inert, meaning they rarely react. Neon is a noble
gas.



2. What is the molar mass of NaCl?
A) 35.45 g/mol
B) 58.44 g/mol
C) 22.99 g/mol
D) 40.00 g/mol

,Correct detailed100% answer: B) 58.44 g/mol
Explanation: 👀 ** Sodium (Na) = 22.99 g/mol, Chlorine (Cl) =
35.45 g/mol. Add them: 22.99 + 35.45 = 58.44 g/mol.


3. Which type of bond involves the sharing of electrons
between atoms? A) Ionic
B) Covalent
C) Metallic
D) Hydrogen

Correct detailed100% answer: B) Covalent
Explanation: 👀 ** Covalent bonds involve sharing electrons
between two nonmetals. Ionic bonds involve transferring
electrons.



4. What is the pH of a solution with [H⁺] = 1 × 10⁻³ M?
A) 3
B) 7
C) 11
D) 0

Correct detailed100% answer: A) 3
Explanation: 👀 ** pH = -log[H⁺] → pH = -log(1 × 10⁻³) = 3.


5. Which element has 12 protons?
A) Carbon
B) Magnesium
C) Aluminum
D) Sodium

,Correct detailed100% answer: B) Magnesium
Explanation: 👀 ** The number of protons equals the atomic
number. Magnesium’s atomic number is 12.


6. What is the chemical formula for sulfuric acid?
A) HCl
B) H₂SO₄
C) HNO₃
D) NaOH

Correct detailed100% answer: B) H₂SO₄
Explanation: 👀 ** Sulfuric acid contains 2 hydrogen atoms, 1
sulfur, and 4 oxygen atoms → H₂SO₄.



7. A solution contains 0.5 moles of solute in 2 liters of
solution. What is its molarity?
A) 0.25 M
B) 1 M
C) 2 M
D) 4 M

Correct detailed100% answer: A) 0.25 M
Explanation: 👀 ** Molarity = moles/volume (L). 0.5 ÷ 2 = 0.25 M.


8. Which of the following is an exothermic reaction?
A) Melting ice
B) Condensation of water vapor
C) Boiling water
D) Evaporation of alcohol

, Correct detailed100% answer: B) Condensation of water vapor
Explanation: 👀 ** Exothermic reactions release heat.
Condensation releases heat to the surroundings.


9. The chemical symbol “Fe” stands for which element?
A) Fluorine
B) Iron
C) Francium
D) Fermium

Correct detailed100% answer: B) Iron
Explanation: 👀 ** Fe comes from the Latin “Ferrum,” meaning
iron.


10. Which of these compounds is ionic?
A) CO₂
B) NaBr
C) CH₄
D) H₂O

Correct detailed100% answer: B) NaBr
Explanation: 👀 ** Ionic compounds form between metals and
nonmetals. NaBr is sodium (metal) + bromine (nonmetal).

11. Which subatomic particle has a negative charge?
A) Proton
B) Neutron
C) Electron
D) Positron

Correct detailed100% answer: C) Electron