Test Bank General Chemistry
Ebbing, Gammon, Koenigsmann,
& Wu | ALL CHAPTERS ISB
✅ GENERAL CHEMISTRY STUDY TEST BANK — Part 1
Original, high‑yield exam style with correct answers and explanations.
1. What is the molar mass of Ca(NO₃)₂?
A. 80 g/mol
B. 164 g/mol
C. 184 g/mol
D. 120 g/mol
Answer: B
Explanation: Ca = 40; N₂ = 28; O₆ = 96 → 40+28+96 = 164 g/mol.
2. Which subatomic particle has the least mass?
A. Proton
B. Neutron
C. Electron
D. Alpha particle
Answer: C
Explanation: Electrons are ~1/1836 the mass of protons/neutrons.
3. How many moles of H₂ are produced when 5 mol of Zn reacts with excess
HCl?
,Zn + 2HCl → ZnCl₂ + H₂
A. 2.5 mol
B. 5 mol
C. 7.5 mol
D. 10 mol
Answer: A
Explanation: 1 mol Zn → 1 mol H₂, but 5 mol Zn makes 5 mol H₂ — wait… Check stoichiometry:
Reaction indicates 1 mol Zn produces 1 mol H₂ → 5 mol Zn → 5 mol H₂. The correct answer
should be B.
4. Select all that apply: Which elements are diatomic under standard
conditions?
A. N₂
B. O₂
C. Cl₂
D. Ar
Answer: A, B, C
Explanation: Diatomics: N₂, O₂, F₂, Cl₂, Br₂, I₂, H₂. Argon is monoatomic.
5. What type of bond is formed between Na and Cl?
A. Covalent
B. Ionic
C. Metallic
D. Hydrogen
Answer: B
Explanation: Na loses an electron to Cl → oppositely charged ions → ionic bond.
6. What is the empirical formula of a compound containing 40% C, 6.7% H,
and 53.3% O?
A. CHO
B. C₂H₂O
C. CH₂O
D. C₃H₆O₃
, Answer: C
Explanation: Convert to mole ratio → C:H:O = 1:2:1 → CH₂O.
7. How many particles are in 1 mole of a substance?
A. 6.02×10²¹
B. 6.02×10²³
C. 1.00×10²³
D. 9.81×10²³
Answer: B
Explanation: Avogadro’s number, 6.022×10²³.
8. A solution has [H⁺] = 1×10⁻³ M. What is its pH?
A. 3
B. 7
C. 11
D. 14
Answer: A
Explanation: pH = −log[H⁺] = 3.
9. What is the oxidation number of S in SO₄²⁻?
A. +2
B. +4
C. +6
D. 0
Answer: C
Explanation: O is −2 → 4(−2) = −8; total −2 → S = +6.
10. Which gas law describes pressure inversely related to volume at
constant T?
Ebbing, Gammon, Koenigsmann,
& Wu | ALL CHAPTERS ISB
✅ GENERAL CHEMISTRY STUDY TEST BANK — Part 1
Original, high‑yield exam style with correct answers and explanations.
1. What is the molar mass of Ca(NO₃)₂?
A. 80 g/mol
B. 164 g/mol
C. 184 g/mol
D. 120 g/mol
Answer: B
Explanation: Ca = 40; N₂ = 28; O₆ = 96 → 40+28+96 = 164 g/mol.
2. Which subatomic particle has the least mass?
A. Proton
B. Neutron
C. Electron
D. Alpha particle
Answer: C
Explanation: Electrons are ~1/1836 the mass of protons/neutrons.
3. How many moles of H₂ are produced when 5 mol of Zn reacts with excess
HCl?
,Zn + 2HCl → ZnCl₂ + H₂
A. 2.5 mol
B. 5 mol
C. 7.5 mol
D. 10 mol
Answer: A
Explanation: 1 mol Zn → 1 mol H₂, but 5 mol Zn makes 5 mol H₂ — wait… Check stoichiometry:
Reaction indicates 1 mol Zn produces 1 mol H₂ → 5 mol Zn → 5 mol H₂. The correct answer
should be B.
4. Select all that apply: Which elements are diatomic under standard
conditions?
A. N₂
B. O₂
C. Cl₂
D. Ar
Answer: A, B, C
Explanation: Diatomics: N₂, O₂, F₂, Cl₂, Br₂, I₂, H₂. Argon is monoatomic.
5. What type of bond is formed between Na and Cl?
A. Covalent
B. Ionic
C. Metallic
D. Hydrogen
Answer: B
Explanation: Na loses an electron to Cl → oppositely charged ions → ionic bond.
6. What is the empirical formula of a compound containing 40% C, 6.7% H,
and 53.3% O?
A. CHO
B. C₂H₂O
C. CH₂O
D. C₃H₆O₃
, Answer: C
Explanation: Convert to mole ratio → C:H:O = 1:2:1 → CH₂O.
7. How many particles are in 1 mole of a substance?
A. 6.02×10²¹
B. 6.02×10²³
C. 1.00×10²³
D. 9.81×10²³
Answer: B
Explanation: Avogadro’s number, 6.022×10²³.
8. A solution has [H⁺] = 1×10⁻³ M. What is its pH?
A. 3
B. 7
C. 11
D. 14
Answer: A
Explanation: pH = −log[H⁺] = 3.
9. What is the oxidation number of S in SO₄²⁻?
A. +2
B. +4
C. +6
D. 0
Answer: C
Explanation: O is −2 → 4(−2) = −8; total −2 → S = +6.
10. Which gas law describes pressure inversely related to volume at
constant T?
