PROFESSIONAL CHEMIST CERTIFICATION
EXAM QUESTION AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A INSTANT
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1. Which branch of chemistry focuses on the study of carbon-containing
compounds?
A. Inorganic chemistry
B. Physical chemistry
C. Organic chemistry
D. Analytical chemistry
Correct Answer: Organic chemistry deals primarily with carbon-based
compounds.
2. The pH of a neutral aqueous solution at 25°C is:
A. 0
B. 1
C. 7
D. 14
A neutral solution has equal concentrations of H⁺ and OH⁻ ions, giving pH
7.
3. Which law states that mass is neither created nor destroyed in a chemical
reaction?
A. Law of Definite Proportions
B. Law of Multiple Proportions
C. Law of Conservation of Mass
, D. Avogadro’s Law
The law of conservation of mass applies to all chemical reactions.
4. What is the SI unit of amount of substance?
A. Gram
B. Kilogram
C. Mole
D. Liter
The mole is the base SI unit for amount of substance.
5. Which subatomic particle determines the chemical identity of an element?
A. Electron
B. Neutron
C. Proton
D. Nucleus
The number of protons defines the atomic number and element identity.
6. Which type of bond involves sharing of electrons?
A. Ionic
B. Metallic
C. Covalent
D. Hydrogen
Covalent bonds form when atoms share electrons.
7. What is the oxidation state of oxygen in most compounds?
A. +2
B. +1
C. –2
D. 0
Oxygen usually has an oxidation state of –2, except in peroxides and OF₂.
8. Which analytical technique separates components based on their
movement through a stationary phase?
A. Spectroscopy
B. Titration
, C. Chromatography
D. Gravimetry
Chromatography separates substances based on differential migration.
9. The ideal gas law is expressed as:
A. PV = nRT
B. PV = nRT
C. V/T = constant
D. P₁V₁ = P₂V₂
The ideal gas law relates pressure, volume, temperature, and moles.
10.What is the primary purpose of a buffer solution?
A. Increase pH
B. Decrease pH
C. Resist changes in pH
D. Neutralize acids completely
Buffers maintain relatively constant pH when acids or bases are added.
11.Which orbital has a dumbbell shape?
A. s
B. p
C. d
D. f
p orbitals have a characteristic dumbbell shape.
12.What is the term for heat absorbed or released at constant pressure?
A. Internal energy
B. Entropy
C. Enthalpy
D. Gibbs free energy
Enthalpy changes occur at constant pressure.
13.Which compound is an Arrhenius acid?
A. NaOH
EXAM QUESTION AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A INSTANT
DOWNLOAD PDF
1. Which branch of chemistry focuses on the study of carbon-containing
compounds?
A. Inorganic chemistry
B. Physical chemistry
C. Organic chemistry
D. Analytical chemistry
Correct Answer: Organic chemistry deals primarily with carbon-based
compounds.
2. The pH of a neutral aqueous solution at 25°C is:
A. 0
B. 1
C. 7
D. 14
A neutral solution has equal concentrations of H⁺ and OH⁻ ions, giving pH
7.
3. Which law states that mass is neither created nor destroyed in a chemical
reaction?
A. Law of Definite Proportions
B. Law of Multiple Proportions
C. Law of Conservation of Mass
, D. Avogadro’s Law
The law of conservation of mass applies to all chemical reactions.
4. What is the SI unit of amount of substance?
A. Gram
B. Kilogram
C. Mole
D. Liter
The mole is the base SI unit for amount of substance.
5. Which subatomic particle determines the chemical identity of an element?
A. Electron
B. Neutron
C. Proton
D. Nucleus
The number of protons defines the atomic number and element identity.
6. Which type of bond involves sharing of electrons?
A. Ionic
B. Metallic
C. Covalent
D. Hydrogen
Covalent bonds form when atoms share electrons.
7. What is the oxidation state of oxygen in most compounds?
A. +2
B. +1
C. –2
D. 0
Oxygen usually has an oxidation state of –2, except in peroxides and OF₂.
8. Which analytical technique separates components based on their
movement through a stationary phase?
A. Spectroscopy
B. Titration
, C. Chromatography
D. Gravimetry
Chromatography separates substances based on differential migration.
9. The ideal gas law is expressed as:
A. PV = nRT
B. PV = nRT
C. V/T = constant
D. P₁V₁ = P₂V₂
The ideal gas law relates pressure, volume, temperature, and moles.
10.What is the primary purpose of a buffer solution?
A. Increase pH
B. Decrease pH
C. Resist changes in pH
D. Neutralize acids completely
Buffers maintain relatively constant pH when acids or bases are added.
11.Which orbital has a dumbbell shape?
A. s
B. p
C. d
D. f
p orbitals have a characteristic dumbbell shape.
12.What is the term for heat absorbed or released at constant pressure?
A. Internal energy
B. Entropy
C. Enthalpy
D. Gibbs free energy
Enthalpy changes occur at constant pressure.
13.Which compound is an Arrhenius acid?
A. NaOH
