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 27 of 45
- A. CH2Br
- B. C2H4Br2
- C. C2H4Br
- D. CH2(Br)2
- E. C2H2(Br)3
Explanation: To determine the molecular formula, first calculate the empirical formula based on the given percentage composition:Convert the percentage…
Correct answer: C2H4Br2- A. 2 M
- B. 0.1 M
- C. 1 M
- D. 0.02 M
Explanation: Na2CO3 = 23(2)+12+16(3) = 46+12+48 = 106 Concentration = Given mass/molar mass Concentration = 106/106 = 1M.
Correct answer: 1 M- A. 2 dm3
- B. 74.5 dm3
- C. 50 dm3
- D. 40 dm3
- E. 20 dm3
Explanation: To determine the volume of KCl obtained in the given equation, we need to know the stoichiometric ratio between KCIO3 and KCl.
Correct answer: 20 dm3- A. Theoretical yield
- B. Actual yield
- C. % yield
- D. Maximum yield
Explanation: % yield is typically referred to as percentage yield. This is determined by dividing the number of moles of the product obtained by the…
Correct answer: % yield- A. C6H12O6
- B. CHO
- C. CH2O
- D. CH2O2
Explanation: The molecular formula for glucose is C6H12O6. The subscripts represent a multiple of the empirical formula.
Correct answer: CH2O- A. 108 grams
- B. 54 grams
- C. 216 grams
- D. 27 grams
- E. 92 grams
Explanation: The decomposition of silver nitrate is represented by the balanced chemical equation:2AgNO3 → 2Ag + 2NO2 + O2This equation shows that 2…
Correct answer: 54 grams- A. Relative number of atoms and electrons
- B. Actual number of atoms
- C. Both relative and actual number of atoms
- D. None of the above
Explanation: The molecular formula provides the actual number of each type of atom present in a specific molecule, such as C6H12O6 for glucose…
Correct answer: Actual number of atoms- A. 6.02 x 10²³
- B. 1.204 x 10²³
- C. 1.806 x 10²³
- D. 2.408 x 10²³
- E. 3.01 x 10²³
Explanation: To determine the number of electrons in 1.6 grams of methane (CH4), we first need to calculate the number of moles of methane present…
Correct answer: 6.02 x 10²³- A. NO
- B. N2O3
- C. N2O4
- D. N2O5
Explanation: Mass of nitrogen is 14 g and mass of oxygen is 16 g. Dividing nitrogen's mass in compound (28g) by 14g gives us 2.
Correct answer: N2O5- A. C2H4
- B. C6H6
- C. C8H8
- D. C4H4
Explanation: Molar mass of CH = 12+1 = 13g Molar mass of the hydrocarbon = 78g as 22.414 dm3 is equal to 1 mol.
Correct answer: C6H6- A. 11 H2O
- B. 11 O2
- C. 11 CO2
- D. 11 H2
Explanation: Comparing reactant and product side we can see that there is a difference of 22 H and 11 O.
Correct answer: 11 H2O- A. 44 dm3
- B. 22.4 dm3
- C. 33.6 dm3
- D. 11.2 dm3
Explanation: In the reaction, 2 moles of H2 react with 1 mole of O2 to form water vapor. Initially, there are 44.8 dm3 of gas (22.4 dm3 of each gas).
Correct answer: 11.2 dm3- A. Empirical formula
- B. Empirical formula mass
- C. Molecular formula
- D. Molecular mass
Explanation: The empirical formula expresses the simplest, most reduced ratio of the different types of atoms in a chemical compound.
Correct answer: Empirical formula- A. 250
- B. 200
- C. 400
- D. 1000
Explanation: The concentration of fluoride in terms of ppm (parts per million) can be calculated as follows: 1 ppm = 1 mg of solute per 1 liter of…
Correct answer: 400- A. 27
- B. 30
- C. 87
- D. 90
Explanation: To calculate the relative atomic mass of M, we can use the fact that the hydride MH3 contains 90% of M by mass.Let the atomic mass of M be…
Correct answer: 27- A. 19.04 mm Hg
- B. 24.2 mm of Hg
- C. 21.42 mm of Hg
- D. 21.4 mm of Hg
Explanation: The vapor pressure of a solution can be calculated using Raoult's law which states that the vapor pressure of a solution is directly…
Correct answer: 19.04 mm Hg- A. 0.5
- B. 0.60
- C. 1.0
- D. 1.50
Explanation: The molar mass of NO2 is approximately 46.01 g/mol. This means that one mole of NO2 weighs 46.01 grams.
Correct answer: 0.5- A. 2.3 g
- B. 19.5 g
- C. 39 g
- D. 78 g
Explanation: To solve this problem, we begin by determining the number of atoms in 4g of calcium.
Correct answer: 2.3 g- A. 5.0
- B. 6.25
- C. 3.125
- D. 2.5
Explanation: Molarity (M)= weight of solute in g / litre ÷ Gram Molecular Weight.Molecular weight of NaOH = (23+16+1) = 4025% NaOH 40gm of NaOH in…
Correct answer: 6.25- A. (6.02 x 10^23 g / 32)
- B. (32 / 6.02 x 10^23) g
- C. 32 g
- D. 0.32 g
Explanation: The mass of 1 mole of oxygen gas (O2) is 16+16 = 32g/mol.1 mole of oxygen gas contains 6.02x1023 molecules.
Correct answer: (32 / 6.02 x 10^23) g