PracticeVideosBlogFlashcardsEspañol
All Practice Exams

Free Practice Questions for Moldova Bacalaureat Chemistry

Exam-style questions and explanations by OpenExamPrep.

✓ No registration✓ No credit card
96+ Questions
100% Free

Loading practice questions...

Same family resources

Explore More Moldova National Baccalaureate Examinations (Examenul Național de Bacalaureat — ANCE)

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

Moldova Bacalaureat — Gagauz Language & Literature

Practice Questions

Moldova Bacalaureat — Geography (Geografie)

Practice Questions

Moldova Bacalaureat — History of Romanians & Universal History

Practice Questions

Moldova Bacalaureat — Romanian as a Second Language (Alolingvi)

Practice Questions

Moldova Bacalaureat — Romanian Language & Literature

Practice Questions

Moldova Bacalaureat — Russian Language & Literature

Practice Questions

Sample Moldova Bacalaureat Chemistry Practice Questions

Try these sample questions to review concepts for the Moldova Bacalaureat Chemistry exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 96+ question experience with AI tutoring.

1A neutral atom of chlorine-37 contains 17 protons. Which combination of subatomic particles is present in the nucleus and electron cloud of this isotope?
A.17 protons, 17 neutrons, and 20 electrons
B.17 protons, 20 neutrons, and 17 electrons
C.20 protons, 17 neutrons, and 17 electrons
D.17 protons, 37 neutrons, and 17 electrons
Explanation: The atomic number (Z = 17) defines the number of protons in the nucleus, which equals 17. In an electrically neutral atom, the number of electrons equals the number of protons (17 electrons). The mass number (A = 37) represents the sum of protons and neutrons (A = Z + N). Therefore, the number of neutrons is N = A - Z = 37 - 17 = 20 neutrons.
2Which set of quantum numbers (n, l, m_l, m_s) is permissible for an electron occupying a 3p atomic orbital?
A.n = 3, l = 0, m_l = 0, m_s = +1/2
B.n = 3, l = 2, m_l = -1, m_s = -1/2
C.n = 3, l = 1, m_l = -1, m_s = +1/2
D.n = 2, l = 1, m_l = +1, m_s = -1/2
Explanation: For a 3p orbital, the principal quantum number is n = 3 and the azimuthal (orbital angular momentum) quantum number is l = 1 (where l = 0 corresponds to s, 1 to p, 2 to d, and 3 to f). The magnetic quantum number m_l can take integer values from -l to +l, meaning m_l ∈ {-1, 0, +1}. The electron spin quantum number m_s must be either +1/2 or -1/2. Thus, n = 3, l = 1, m_l = -1, m_s = +1/2 is fully permissible.
3According to Hund's rule and the Pauli exclusion principle, how are the valence electrons distributed in the ground-state nitrogen atom (Z = 7)?
A.Three unpaired electrons with parallel spins occupying three separate 2p orbitals (2p_x^1 2p_y^1 2p_z^1)
B.One paired electron pair in 2p_x and one single electron in 2p_y, leaving 2p_z completely vacant
C.Three electrons paired up in the 2s subshell with opposite spins, leaving the 2p subshell with only one electron
D.Five equivalent electrons distributed equally across all five degenerate 2d orbitals
Explanation: Nitrogen has 7 electrons with the ground-state electron configuration 1s² 2s² 2p³. According to Hund's rule of maximum multiplicity, when filling degenerate orbitals (orbitals of equal energy such as 2p_x, 2p_y, and 2p_z), electrons occupy them singly with parallel spins before any pairing occurs. Therefore, nitrogen possesses three unpaired valence electrons in the 2p subshell: 2p_x¹ 2p_y¹ 2p_z¹.
4How do first ionization energy and atomic radius generally vary across Period 3 of the periodic table from sodium (Na) to argon (Ar)?
A.First ionization energy decreases and atomic radius decreases
B.First ionization energy decreases and atomic radius increases
C.First ionization energy increases and atomic radius increases
D.First ionization energy generally increases and atomic radius decreases
Explanation: Across Period 3 from left to right (Na to Ar), the nuclear charge (Z) increases by one unit for each successive element while electrons are added to the same principal energy level (n = 3). The core electron shielding remains relatively constant, resulting in a steady increase in effective nuclear charge (Z_eff). This stronger nuclear attraction pulls valence electrons closer to the nucleus (decreasing atomic radius) and requires significantly more energy to remove an electron (generally increasing first ionization energy).
5Which of the following halogen elements possesses the highest Pauling electronegativity?
A.Chlorine (Cl)
B.Fluorine (F)
C.Bromine (Br)
D.Iodine (I)
Explanation: Fluorine (F) is the most electronegative element in the entire periodic table, assigned a value of 3.98 (approximately 4.0) on the Pauling scale. Within Group 17 (the halogens), electronegativity decreases descending the group (F > Cl > Br > I) because additional electron shells increase the atomic radius and shielding, weakening the attraction between the nucleus and bonding electrons.
6Which of the following substances contains exclusively non-polar covalent bonds in its chemical structure?
A.Nitrogen gas (N2)
B.Hydrogen chloride (HCl)
C.Potassium chloride (KCl)
D.Water (H2O)
Explanation: In molecular nitrogen (N2), two identical nitrogen atoms share three pairs of electrons in a triple covalent bond (:N≡N:). Because both atoms have identical electronegativities (Δχ = 0), the electron cloud is shared equally with no dipole moment, forming a pure non-polar covalent bond.
7Why does water (H2O, boiling point 100 °C) have a drastically higher boiling point than hydrogen sulfide (H2S, boiling point -60 °C), despite H2S having a greater molecular mass?
A.H2S contains stronger covalent bonds within the molecule that prevent vaporization
B.Water molecules are held together by metallic bonds between hydrogen atoms
C.Intermolecular hydrogen bonding between H2O molecules is significantly stronger than the dipole-dipole and London dispersion forces in H2S
D.Liquid H2S forms an ionic network lattice that decomposes below room temperature
Explanation: Oxygen is highly electronegative and has a small atomic radius, making the O-H bonds in water strongly polar and allowing oxygen's lone pairs to form strong intermolecular hydrogen bonds. Hydrogen bonding creates an extensive tetrahedral network in liquid water requiring significant thermal energy to overcome (boiling point 100 °C). Sulfur is less electronegative and larger, so H2S cannot form substantial hydrogen bonds and is held only by weaker dipole-dipole interactions and London dispersion forces, boiling at -60 °C.
8Why does granulated zinc react with 1.0 M hydrochloric acid at a significantly faster rate than an equal mass of a solid zinc block at the same temperature?
A.Granulated zinc has a lower activation energy for the reaction than a zinc block
B.Granulated zinc exposes a much larger surface area, increasing the frequency of effective collisions with hydronium ions
C.Granulated zinc shifts the chemical equilibrium position further toward the products
D.Granulated zinc increases the rate constant k by acting as an autocatalyst
Explanation: According to collision theory, heterogeneous reactions between solids and liquids occur only at the interface. Granulating the zinc divides the solid into smaller particles, vastly increasing the contact surface area exposed to aqueous H+ ions. A higher surface area results in a higher frequency of collisions per unit time, thereby accelerating the reaction rate without altering the activation energy, rate constant, or equilibrium constant.
9Which of the following elements exhibits an anomalous ground-state electron configuration characterized by a half-filled d subshell?
A.Chromium (Z = 24), [Ar] 3d^5 4s^1
B.Vanadium (Z = 23), [Ar] 3d^3 4s^2
C.Manganese (Z = 25), [Ar] 3d^5 4s^2
D.Iron (Z = 26), [Ar] 3d^6 4s^2
Explanation: Based on the standard Aufbau filling order, chromium (Z = 24) would be expected to have the configuration [Ar] 3d^4 4s^2. However, the energy difference between the 3d and 4s subshells is very small, and a spherically symmetric, half-filled 3d^5 subshell provides extra exchange energy stability. Consequently, one 4s electron is promoted to the 3d subshell, giving chromium the anomalous ground-state configuration [Ar] 3d^5 4s^1.
10According to the Valence Shell Electron Pair Repulsion (VSEPR) theory, what are the electron domain geometry, molecular geometry, and approximate bond angle of the ammonia molecule (NH3)?
A.Trigonal planar electron geometry, trigonal planar molecular geometry, 120°
B.Tetrahedral electron geometry, tetrahedral molecular geometry, 109.5°
C.Tetrahedral electron geometry, trigonal pyramidal molecular geometry, ~107°
D.T-shaped electron geometry, trigonal pyramidal molecular geometry, 90°
Explanation: In NH3, the central nitrogen atom is surrounded by 4 electron domains: 3 single covalent N-H bonding pairs and 1 non-bonding lone pair (steric number = 4). The electron domain geometry is tetrahedral. Because lone pair-bonding pair repulsions are greater than bonding pair-bonding pair repulsions, the lone pair compresses the H-N-H bond angles from the ideal tetrahedral angle of 109.5° down to approximately 107.3° (~107°). The resulting molecular geometry (spatial arrangement of atoms) is trigonal pyramidal.

About the Moldova Bacalaureat Chemistry Exam

Examenul Național de Bacalaureat — Chimie is a current Moldova national Bacalaureat assessment administered by ANCE. Published study domains include General chemistry, Inorganic chemistry, Organic chemistry, Chemical calculations. This local bank is an independent English-language MCQ study adaptation. It is not an official translation, not an official-format simulation, and does not replace practice with the official written tasks.

Exam sponsor: National Agency for Curriculum and Evaluation (ANCE), Ministry of Education and Research of the Republic of Moldova. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Official assessment: written paper combining chemical knowledge, equations, qualitative reasoning, and quantitative problems. This local bank is an independent English-language MCQ study adaptation. It is not an official translation, not an official-format simulation, and does not replace practice with the official written tasks.

Time Limit

180 minutes

Passing Score

A final Bacalaureat subject mark of at least 5.00 on the 10-point scale is required; the raw-point conversion is published with the official marking scheme.

Exam / Certification Fees

ANCE does not publish a separate per-paper fee for school-registered candidates.

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

Official percentage not published

General chemistry

Atomic structure, bonding, energetics, kinetics, equilibrium, acids and bases, and redox.

Official percentage not published

Inorganic chemistry

Properties and reactions of elements and inorganic compounds, identification, and industrial processes.

Official percentage not published

Organic chemistry

Hydrocarbons, oxygen- and nitrogen-containing compounds, biomolecules, polymers, and transformations.

Official percentage not published

Chemical calculations

Stoichiometry, solutions, gases, yields, electrolysis, and composition problems.

Preparing for the Moldova Bacalaureat Chemistry Exam

What You Need to Know

  • Passing score: A final Bacalaureat subject mark of at least 5.00 on the 10-point scale is required; the raw-point conversion is published with the official marking scheme.
  • Assessment: Official assessment: written paper combining chemical knowledge, equations, qualitative reasoning, and quantitative problems. This local bank is an independent English-language MCQ study adaptation. It is not an official translation, not an official-format simulation, and does not replace practice with the official written tasks.
  • Time limit: 180 minutes
  • Exam / certification fees: ANCE does not publish a separate per-paper fee for school-registered candidates. Official sources

Using Our Practice Resources

  • Work through all 96 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

Moldova Bacalaureat Chemistry: Suggested Study Strategy

1Use the official ANCE program as the checklist for topics and competencies.
2After MCQ review, practise the official written task types under the published time conditions.
3Check answers against official terminology, source texts, diagrams, or calculations rather than memorizing option positions.

Frequently Asked Questions

Is this the official exam format?

No. This local bank is an independent English-language MCQ study adaptation. It is not an official translation, not an official-format simulation, and does not replace practice with the official written tasks.

What language is the official assessment offered in?

Confirmed 2026 paper language code(s): ro, ru, en, fr.

How many questions are on the official paper?

The official program does not promise a fixed future item count; consult the current ANCE paper and marking scheme.