CHEM 103 / CHEM103 Final Exam:
(Latest 2025/ 2026 Update) General
Chemistry I W/ Lab | Questions &
Answers PLUS RATIONALES| Grade A|
100% Correct (Verified Solutions)-
Portage Learning
1.
What is the atomic number of an element?
A. Number of neutrons
B. Number of protons
C. Number of electrons + neutrons
D. Atomic mass
Answer: B. Number of protons
Rationale: Atomic number defines the number of protons in the nucleus.
2.
Which of the following is an example of an ionic bond?
A. H₂O
B. CO₂
C. NaCl
D. CH₄
Answer: C. NaCl
Rationale: Ionic bonds form between metals and nonmetals via electron transfer.
3.
,What is the molar mass of H₂O?
A. 16 g/mol
B. 18 g/mol
C. 20 g/mol
D. 22 g/mol
Answer: B. 18 g/mol
Rationale: 2(1) + 16 = 18 g/mol.
4.
Which law states that matter cannot be created or destroyed?
A. Boyle’s Law
B. Charles’ Law
C. Law of Conservation of Mass
D. Avogadro’s Law
Answer: C. Law of Conservation of Mass
Rationale: Mass remains constant in chemical reactions.
5.
What is the pH of a neutral solution?
A. 0
B. 5
C. 7
D. 14
Answer: C. 7
Rationale: Neutral solutions have equal H⁺ and OH⁻ concentrations.
6.
Which particle has a negative charge?
,A. Proton
B. Neutron
C. Electron
D. Nucleus
Answer: C. Electron
Rationale: Electrons carry a -1 charge.
7.
What type of reaction is: A + B → AB?
A. Decomposition
B. Synthesis
C. Combustion
D. Single replacement
Answer: B. Synthesis
Rationale: Two substances combine to form one product.
8.
Which gas law relates pressure and volume?
A. Charles’ Law
B. Boyle’s Law
C. Avogadro’s Law
D. Dalton’s Law
Answer: B. Boyle’s Law
Rationale: P₁V₁ = P₂V₂ (inverse relationship).
9.
What is the oxidation number of oxygen in most compounds?
A. +1
B. +2
, C. -1
D. -2
Answer: D. -2
Rationale: Oxygen typically has a -2 oxidation state.
10.
Which element is a noble gas?
A. Oxygen
B. Nitrogen
C. Neon
D. Sodium
Answer: C. Neon
Rationale: Noble gases are in Group 18.
11.
What is 1 mole equal to?
A. 6.022 × 10²¹
B. 6.022 × 10²²
C. 6.022 × 10²³
D. 6.022 × 10²⁴
Answer: C. 6.022 × 10²³
Rationale: Avogadro’s number.
12.
Which is a strong acid?
A. CH₃COOH
B. HCl
C. NH₃
D. H₂O
(Latest 2025/ 2026 Update) General
Chemistry I W/ Lab | Questions &
Answers PLUS RATIONALES| Grade A|
100% Correct (Verified Solutions)-
Portage Learning
1.
What is the atomic number of an element?
A. Number of neutrons
B. Number of protons
C. Number of electrons + neutrons
D. Atomic mass
Answer: B. Number of protons
Rationale: Atomic number defines the number of protons in the nucleus.
2.
Which of the following is an example of an ionic bond?
A. H₂O
B. CO₂
C. NaCl
D. CH₄
Answer: C. NaCl
Rationale: Ionic bonds form between metals and nonmetals via electron transfer.
3.
,What is the molar mass of H₂O?
A. 16 g/mol
B. 18 g/mol
C. 20 g/mol
D. 22 g/mol
Answer: B. 18 g/mol
Rationale: 2(1) + 16 = 18 g/mol.
4.
Which law states that matter cannot be created or destroyed?
A. Boyle’s Law
B. Charles’ Law
C. Law of Conservation of Mass
D. Avogadro’s Law
Answer: C. Law of Conservation of Mass
Rationale: Mass remains constant in chemical reactions.
5.
What is the pH of a neutral solution?
A. 0
B. 5
C. 7
D. 14
Answer: C. 7
Rationale: Neutral solutions have equal H⁺ and OH⁻ concentrations.
6.
Which particle has a negative charge?
,A. Proton
B. Neutron
C. Electron
D. Nucleus
Answer: C. Electron
Rationale: Electrons carry a -1 charge.
7.
What type of reaction is: A + B → AB?
A. Decomposition
B. Synthesis
C. Combustion
D. Single replacement
Answer: B. Synthesis
Rationale: Two substances combine to form one product.
8.
Which gas law relates pressure and volume?
A. Charles’ Law
B. Boyle’s Law
C. Avogadro’s Law
D. Dalton’s Law
Answer: B. Boyle’s Law
Rationale: P₁V₁ = P₂V₂ (inverse relationship).
9.
What is the oxidation number of oxygen in most compounds?
A. +1
B. +2
, C. -1
D. -2
Answer: D. -2
Rationale: Oxygen typically has a -2 oxidation state.
10.
Which element is a noble gas?
A. Oxygen
B. Nitrogen
C. Neon
D. Sodium
Answer: C. Neon
Rationale: Noble gases are in Group 18.
11.
What is 1 mole equal to?
A. 6.022 × 10²¹
B. 6.022 × 10²²
C. 6.022 × 10²³
D. 6.022 × 10²⁴
Answer: C. 6.022 × 10²³
Rationale: Avogadro’s number.
12.
Which is a strong acid?
A. CH₃COOH
B. HCl
C. NH₃
D. H₂O
