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.
Last updated
Read the Fundamental Concepts of Chemistry notesFree MDCAT chapter notes with key terms894 questions · page 45 of 45
- A. 180g
- B. 81g
- C. 1.8g
- D. 0.18g
Explanation: The solution for this question is given below:
Correct answer: 1.8g- A. 6.022 × 10^23 amu
- B. 6.022 × 10^-23 amu
- C. 6.022 × 10^-24 amu
- D. 6.022 × 10^24 amu
Explanation: As 1 a.m.u is equal to 1.66 x 10^-24 g conversely 1 gram is equal to 6.022 x 10^23 amu.For example: 1 carbon atom = 12 amu 1 mole of…
Correct answer: 6.022 × 10^23 amu- A. 0.12 kg of 6C12
- B. 1.2 kg of 6C12 atom
- C. 0.012 kg of 6C12 atom
- D. 0.12 kg of 8O16
Explanation: One mole is defined as the amount of substance containing as many elementary entities (atoms, molecules, etc.) as there are atoms in 12…
Correct answer: 0.012 kg of 6C12 atom- A. 0.20 x 3.01 x 10^23
- B. 0.20 x 2.016
- C. 0.70 x 6.02 x 10^23
- D. 1.008 x 6.02 x 10^23
Explanation: To find the number of molecules in 0.20 g of hydrogen gas, first recognize that hydrogen gas (H2) is diatomic.
Correct answer: 0.20 x 3.01 x 10^23- A. 0.0030 NA
- B. 0.25 NA
- C. 3.0 NA
- D. 4.0 N A
Explanation: The number of atoms in a sample can be determined by first calculating the number of moles using the formula: Number of moles = Mass /…
Correct answer: 0.25 NA- A. Avogadro's Law
- B. Graham's Law
- C. Dalton's Law
- D. Hund's Rule
Explanation: The correct answer is Avogadro's Law. This fundamental principle states that equal volumes of gases, at the same temperature and pressure…
Correct answer: Avogadro's Law- A. 3.0115 x 10^24
- B. 6.023 x 10^24
- C. 6.023 x 10^23
- D. 5.0 x 10^23
Explanation: 5 moles of water contains 5 moles of H2, therefore contains 10 moles of H atoms.The number of atoms in one mole of a substance is given by…
Correct answer: 6.023 x 10^24- A. 6.023 x 10^23
- B. 6.525 x 10^24
- C. 2.408 x 10^23
- D. 6.023 x 10^22
Explanation: The chemical formula for hydrated ferrous sulfate is FeSO4·7H2O, which includes 4 oxygen atoms from the sulfate ion (SO4) and 7 oxygen…
Correct answer: 6.525 x 10^24889. 117.0g of NaCl have
- A. 12.04 x 10^23 Formula unit of NaCl
- B. 12.04 x 10^22 Formula unit of NaCl
- C. 12.04 x 10^23 Molecules of NaCl
- D. 6.023 x 10^23 Molecules of NaCl
Explanation: Option A is correct.To calculate the number of formula units of NaCl in 117.0g of NaCl, we can use the following steps: Calculate the…
Correct answer: 12.04 x 10^23 Formula unit of NaCl- A. 100g
- B. 150g
- C. 200g
- D. 300g
Explanation: Write the balanced chemical equation: CaCO3(s) -> CaO(s) + CO2(g)Calculate the moles of CO2:At STP, 1 mole of any gas occupies 22.4…
Correct answer: 200g- A. 6.023x10^22
- B. 6.023x10^21
- C. 6.023x10 ^23
- D. 4.02x10^23
Explanation: One mole of any substance contains 6.023 x 10^23 particles (atoms, molecules, or ions).
Correct answer: 6.023x10 ^23- A. 8 moles of O2
- B. 16 moles of H
- C. 2 molecules of CH
- D. One atom of Sulphur
Explanation: One molecule of oxygen (O2) has a molecular mass of approximately 32 atomic mass units (amu).
Correct answer: One atom of Sulphur- A. Theoretical yield
- B. Practical yield
- C. Percentage yield
- D. All of above
Explanation: Stoichiometry uses the balanced chemical equation to calculate how much product can theoretically form from given amounts of…
Correct answer: Theoretical yield- A. 2.0 X27/150 x100
- B. 2.0/10 X 2 X 27/150 X 100
- C. 2.0/10 X 27/1500 X 100
- D. 2.0/10 X 150/3 X 27 X 100
Explanation: Mass of aluminum in formula: 2×27=54 gMolar mass of Al₂S₃: 2×27+3×32=54+96=150 g54/150x100=36%
Correct answer: 2.0 X27/150 x100