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 26 of 45
- A. % yield
- B. Theoretical yield
- C. Expected yield
- D. All of these
Explanation: The percentage yield of a reaction is a measure of its efficiency and provides insight into how well the reaction proceeds in practice…
Correct answer: % yield- A. Some product is lost in the experiment
- B. Reversible reaction may occur
- C. Errors are made in weighing the reactants and the products
- D. The given statement is not correct
Explanation: This answer is correct because actual yield is always less than theoretical yield as theoretical yield is the maximum possible yield in a…
Correct answer: The given statement is not correct- A. Actual yield
- B. Ideal yield
- C. Practical yield
- D. Experimental yield
Explanation: This answer is the best as the 64g of SO2 produced is actual yield and the theoretical yield is also 64g hence this is considered as ideal…
Correct answer: Ideal yield- A. Theoretical yield
- B. Expected yield
- C. Actual yield
- D. %age yield
Explanation: The quantity of a product that is actually produced in a chemical reaction is called the actual yield because it represents the amount of…
Correct answer: Actual yield- A. Side reactions may produce by-products
- B. Some reactions are reversible
- C. Mechanical losses occur during processes like filtration and distillation
- D. All of these
Explanation: This answer is correct as all the above options effects the actual yield of a chemical reaction hence this is the best possible option.
Correct answer: All of these- A. C9H18O9
- B. CH2O
- C. C6H12O6
- D. C2H4O2
Explanation: E.F: CH2O=> Empirical formula mass= (1x12)+(2x1)+(1x16) = 30=> n= Molecular Mass/E.F.Mass =180/30= 6=> Molecular formula= n x E.F = 6 x…
Correct answer: C6H12O6- A. 4.
- B. 8.
- C. 16.
- D. 32.
Explanation: H2 + O -> H2O =>O : H2O 1 : 1 X : 0.5 X= 0.5 mol of O atom => Mole=Mass/Mr Mass=Mole x Mr Mass= 0.5 x 16 Mass= 8 g.
Correct answer: 8.- A. N2
- B. H2
- C. NH3
- D. none of these
Explanation: No reagent is the limiting reagent because the number of moles of reactant given is same as the balanced chemical reaction.
Correct answer: none of these- A. 75
- B. 40
- C. 56
- D. 71
Explanation: Mr of CaCO3 => 40 + 12 + (3x16) => 100g/molMr of CaO => 40 + 16 => 56g/molCaCO3-----CaO+CO2100g. 56g25g.
Correct answer: 71- A. 0.136
- B. 0.272
- C. 0.816
- D. 0.0227
Explanation: Following is the solution to this question:
Correct answer: 0.0227- A. 55 ml
- B. 58 ml
- C. 70 ml
- D. 79 ml
Explanation: Following is the solution to this question:
Correct answer: 70 ml- A. 20%
- B. 60%
- C. 80%
- D. 50%
Explanation: The formula for calculating the average atomic mass is[ (Mass of one isotope x percentage abundance) + (mass of other isotope x percentage…
Correct answer: 20%513. The amount (in liters) of Oxygen at STP that is required for the combustion of 4gm of ethylene is :
- A. 96 liters
- B. 9.6 liters
- C. 44.8 liters
- D. 7.2 liters
Explanation: Your reaction will be C2H4 + 3O2 -> 2CO2 + 2H2O 4g of ethylene is 1/7 mole 1 ethylene reacts with 3O2 1/7 will react with x X= 3/7 moles…
Correct answer: 9.6 liters- A. Carbon - 13
- B. Neon - 20
- C. Carbon - 12
- D. Nucleon number
Explanation: By international agreement in 1961 for determining atomic masses, carbon-12 a distinct atom of carbon was chosen as standard with its…
Correct answer: Carbon - 12- A. 5
- B. 10
- C. 10.5
- D. 15
- E. 25
Explanation: Consider that no. of moles of reactants = volume of the reactants.As the molar ratio between C3H6 and O2 is 1:5, the volume ratio is also…
Correct answer: 25- A. C3H4O3
- B. C3H4O6
- C. CH4O3
- D. C6H4O3
- E. C2H5O3
Explanation: The empirical formula is the ratio between the number of atoms of different elements which is present in the molecule of the given…
Correct answer: C3H4O3- A. 14 g
- B. 71 g
- C. 11 g
- D. 2 g
- E. 10 g
Explanation: Limestone is primarily composed of calcium carbonate (CaCO3). When heated, it decomposes according to the reaction:CaCO3 --> CaO + CO2From…
Correct answer: 11 g- A. 12.04 x 10^23
- B. 6.02 x 10^23
- C. 3.01 x 10^23
- D. 1.008
- E. 2
Explanation: 1 mole of hydrogen contains = 2×1 = 2g2g of H2 contain = 2/2 × avogadro number = 1 × 6.022 × 10²³ = 6.022 × 10²³ molecules.
Correct answer: 6.02 x 10^23- A. 1:2:5
- B. 5:1:2
- C. 2:5:3
- D. 5:1:3
Explanation: We have to calculate moles for each of the elements givenFor CO2 mass if given so use the formulamoles = mass/mr (Mr = 12 + 32 = 44)moles…
Correct answer: 5:1:3- A. ½
- B. 8/9
- C. 1/9
- D. 16/17
Explanation: According to Dalton's law of partial pressure, the total pressure of a mixture of gases is the sum of the partial pressure of the gases in…
Correct answer: 8/9