Free Fundamental Concepts of Chemistry MCQs with Answers
894 Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.
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Read the Fundamental Concepts of Chemistry notesFree MDCAT chapter notes with key terms894 questions · page 4 of 45
- A. 80%
- B. 30%
- C. 40%
- D. 20%
Explanation: Using CaCO3 = 40 + 12 + (3 x 16) = 100 g mol^-1, the calcium percentage is (40 g mol^-1 / 100 g mol^-1) x 100 = 40%.
Correct answer: 40%- A. 0.25
- B. 0.5
- C. 0.75
- D. 1
Explanation: One mole of CO2 contains two moles of oxygen atoms, equal to 2 x 16 g = 32 g of oxygen.
Correct answer: 0.5- A. oxygen
- B. carbon
- C. tin
- D. chlorine
Explanation: Tin has the greatest number of naturally occurring stable isotopes among the listed elements, with ten commonly recognized stable…
Correct answer: tin- A. 280
- B. 300
- C. 154
- D. 54
Explanation: For isotopes with even atomic number and even mass number, both the proton number and neutron number are even, a combination that gives…
Correct answer: 154- A. Isotopes with odd atomic number are abundant
- B. Isotopes with odd atomic number and even mass number are abundant
- C. Isotopes with even atomic number and even mass number are abundant
- D. Isotopes with even atomic number and odd mass no are abundant
Explanation: Nuclei with even atomic number and even mass number have both an even proton number and an even neutron number, so the nucleons can be…
Correct answer: Isotopes with even atomic number and even mass number are abundant- A. 1-mole molecules of water
- B. 1-gram molecule of water
- C. 3-gram atoms
- D. all
Explanation: The molar mass of water is 2 x 1 + 16 = 18 g mol^-1, so 18 g of water is 1 mol of H2O molecules and is also called 1 gram-molecule.
Correct answer: all- A. 40g
- B. 43.6g
- C. 45g
- D. 41.4g
Explanation: Percentage yield = actual yield/theoretical yield x 100, so theoretical yield = 24 g x 100/55 = 43.64 g, approximately 43.6 g.
Correct answer: 43.6g- A. Practical yield
- B. Theoretical yield
- C. Actual yield
- D. NOT
Explanation: The balanced chemical equation gives the stoichiometric maximum product that can form when the limiting reactant reacts completely, called…
Correct answer: Theoretical yield- A. Anemic
- B. Cannot be determined
- C. Normal
- D. Polycythemic
Explanation: To determine whether Jimmy is anemic or not, we need to calculate his hemoglobin count based on the given red blood cell count.One red…
Correct answer: Anemic- A. 1.07 kg
- B. 48.9 g
- C. 0.897 g
- D. 0.489 kg
Explanation: Each student requires 10 g of NaOH, therefore, the total amount of NaOH required for 42 students is:10 g/student x 42 students = 420 gThe…
Correct answer: 0.489 kg- A. 0.0177
- B. 0.001
- C. 0.5
- D. 0.244
Explanation: Mole fraction of a component X in a solution is defined as the ratio of the number of moles of X to the total number of moles of all…
Correct answer: 0.0177- A. Y = 13%, Ba = 41%, Cu = 29%, O = 17%
- B. Y = 17%, Ba = 39%, Cu = 23%, O = 21%
- C. Y = 15%, Ba = 52%, Cu = 10%, O = 23%
- D. Y = 19%, Ba = 41%, Cu = 31%, O = 9%
Explanation: To find the mass percentage of each element in YBa₂Cu₃O₇, we need to first calculate its molar mass, which is:1(Y) + 2(Ba) + 3(Cu) + 7(O)…
Correct answer: Y = 13%, Ba = 41%, Cu = 29%, O = 17%- A. 1565.72 kg
- B. 965.46 kg
- C. 2759.81 kg
- D. 2846.12 kg
Explanation: To calculate the amount of H3PO4 produced, we need to first find the amount of tetraphosphorus decaoxide (P4O10) produced and then the…
Correct answer: 2759.81 kg- A. 0.2m
- B. 0.2mm
- C. 0.2nm
- D. 0.2pm
Explanation: The diameter of an atom is on the order of angstroms (Å) or nanometers (nm).
Correct answer: 0.2nm- A. Atomic number
- B. Relative abundance
- C. Electronic configuration
- D. F-, Ne, Na+
Explanation: A mass spectrometer is a device used to determine the mass-to-charge ratio of ions.
Correct answer: Relative abundance- A. Same number of neutrons
- B. Same mass number
- C. Same physical properties
- D. Same chemical properties
Explanation: Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
Correct answer: Same chemical properties- A. 6.022x10^23 atoms of oxygen
- B. 22-gram electrons
- C. 6.022x10^23 atoms of carbon
- D. both b & c
Explanation: A mole is a unit used to express the amount of a substance, and it contains Avogadro's number of entities (atoms, molecules, ions, etc.)…
Correct answer: 6.022x10^23 atoms of carbon- A. volume of particles
- B. number of particles
- C. mass of particles
- D. all of the above
Explanation: Avogadro's number (approximately 6.022x10^23) represents the number of entities (atoms, molecules, ions, etc.) in one mole of a substance.
Correct answer: number of particles- A. Formula unit
- B. Empirical formula
- C. molecular formula
- D. Formula mass
Explanation: This term is not used for ionic compounds. Molecular formulas are specifically associated with covalent compounds, where discrete…
Correct answer: molecular formula- A. 0.18mole
- B. 0.27 mole
- C. 0,24 mole
- D. 0.09 mole
Explanation: To determine the amount of product formed in a chemical reaction, we can use the stoichiometry of the reaction.
Correct answer: 0.18mole