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 10 of 45
- A. No. of moles of reactants and products are same
- B. Unequal no of moles
- C. Both
- D. None of these
Explanation: The equilibrium constant (Kc for concentration-based, Kp for pressure-based) has units only when the number of moles of reactants and…
Correct answer: Unequal no of moles- A. 1 mole of CH4 contains
- B. 4 g-atom of hydrogen
- C. 1.81 x 10^23 molecules of CH4
- D. 3.0 g of carbon
Explanation: Correct Option: a. 6.02 x 10^23 atoms of HOne mole of CH4 contains 6.02 x 10^23 atoms of H because:Avogadro's constant: This constant…
Correct answer: 1 mole of CH4 contains- A. 011
- B. 0.90
- C. 1.0
- D. 1.11
Explanation: We can use the ideal gas law to solve this problem. The ideal gas law relates the pressure (P), volume (V), temperature (T), and number of…
Correct answer: 1.0- A. 1.2 x 10^23
- B. 6 x 10^22
- C. 6 x 10^23
- D. 2 x 10^23
Explanation: Correct Option: a. 1.2 x 10^23Here's how we can calculate the number of oxygen atoms in 4.4g of carbon dioxide:1.
Correct answer: 1.2 x 10^23- A. 2.4 NA2.4 NA
- B. 4.2 NA
- C. 1.6 NA
- D. 3.2 NA
Explanation: To determine the number of valence electrons in 4.2 g of nitride ions (N³⁻), we need to follow these steps:Calculate the number of moles…
Correct answer: 1.6 NA- A. 0.1M
- B. 0.2M
- C. 0.05M
- D. 0.25M
Explanation: When equal volumes of 0.1 M AgNO3 and 0.1 M NaCl are mixed together, the following reactions occur:Initial concentrations:[Ag⁺] = 0.1 M…
Correct answer: 0.05M- A. 22.4
- B. 2.24
- C. 20.16
- D. 2.016
Explanation: Here's how to solve the problem:Calculate the amount of pure calcium carbonate (CaCO₂) in the limestone:Mass of limestone = 10 gPurity of…
Correct answer: 2.016- A. C3H5O2
- B. C6H10O4
- C. C3H10O2
- D. C4H10O2
Explanation: Here's how to solve the problem to find the molecular formula of the organic compound:Calculate the percentage of oxygen:% of oxygen =…
Correct answer: C4H10O2- A. 24
- B. 2 x 10^20
- C. 1020
- D. 6.02 x 10^23
Explanation: Here's how to calculate the number of atoms in 0.004g of magnesium:Calculate the number of moles of magnesium:Mass of magnesium (m) =…
Correct answer: 1020- A. 88g
- B. 44g
- C. 32g
- D. 22g
Explanation: Here's how to solve the problem:STP conditions:Standard Temperature and Pressure (STP) define a temperature of 0°C (273.15 K) and a…
Correct answer: 22g- A. 0.32g
- B. 0.64g
- C. 0.16g
- D. 0.96g
Explanation: Here's how to solve the problem:Convert volume to moles:We are given the volume of oxygen at STP: 112 mL.We need to convert this volume to…
Correct answer: 0.16g- A. 5.5g
- B. 11g
- C. 22g
- D. 33g
Explanation: Here's how to solve the problem:Set up the balanced chemical equation:CaCO3 (s) + 2 HCl (aq) -> CaCl2 (aq) + CO2 (g) + H2O (l)Calculate…
Correct answer: 22g- A. Decrease twice
- B. Increase two fold
- C. Remains unchanged
- D. Be a function of the molecular mass of substance
Explanation: The standard for atomic masses is based on the carbon-12 isotope, where one mole of carbon-12 atoms is assigned a mass of exactly 12…
Correct answer: Increase two fold- A. 10mL of H2
- B. 5mL of H2
- C. 10mL of O2
- D. 5mL of O2
Explanation: Here's how to solve the problem:Write the balanced chemical equation:2 H₂ + O₂ → 2 H₂OConvert volumes to moles:Use the ideal gas law (PV =…
Correct answer: 5mL of O2- A. 34.8
- B. 3.48
- C. 3.74
- D. 348
Explanation: We can calculate the kinetic energy (KE) of one mole of an ideal gas using the formula:KE = (3/2) * R * Twhere:KE is the kinetic energy in…
Correct answer: 3.74- A. Thermochemistry
- B. Electrochemistry
- C. Biochemistry
- D. None
Explanation: Electrochemistry is the branch of chemistry that deals with the study of the interchange of chemical energy and electrical energy between…
Correct answer: Electrochemistry- A. 11.2%
- B. 9.09%
- C. 13.1%
- D. 14.25%
Explanation: The correct option for the percentage by weight of NaCl in the solution is:b.
Correct answer: 9.09%- A. 0.1M
- B. 0.2M
- C. 0.05M
- D. 0.25M
Explanation: When equal volumes of 0.1 M AgNO3 and 0.1 M NaCl are mixed, the following reaction occurs:AgNO3 (aq) + NaCl (aq) -> AgCl (s) + NaNO3…
Correct answer: 0.05M- A. kc=[N2O4]/[NO2]
- B. kc=[N2][O4]/[NO2]
- C. kc=[N2O4]/[NO2]2
- D. kc=[NO2]2 /[N2O4]
Explanation: The equilibrium constant (Kc) for a chemical reaction relates the concentrations of products and reactants at equilibrium.
Correct answer: kc=[NO2]2 /[N2O4]- A. Increases
- B. Remains the same
- C. Decreases
- D. May decrease or increase
Explanation: In most cases, the rate of a reaction decreases with the passage of time(b).
Correct answer: Decreases