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 41 of 45
- A. One mole of water
- B. One mole of CH4
- C. One mole of glucose
- D. One mole of H2O2
Explanation: This answer is correct because one mole of glucose has highest number of atoms.
Correct answer: One mole of glucose- A. A limiting reagent is consumed at the end of the reaction
- B. Actual yield is always greater than theoretical yield
- C. Stoichiometric calculation can be only done if no side reaction happens
- D. The empirical formula in molecular formula of some of the compounds are same
Explanation: Actual yield is less than theoretical yield due to the following reasons i) side reactions may produce by-products ii) some reactions are…
Correct answer: Actual yield is always greater than theoretical yield- A. 24.5g H2SO4
- B. This answer is incorrect because the non limiting reagent is NaOH (in excess).
- C. 46.5g NaOH
- D. 60g NaOH
Explanation: Mr of NaOH= 23 + 16 + 1 = 40g/mol Mr of H2SO4= (2x1) + 32 + (4x16) = 98g/mol 2NaOH + H2SO4 => Na2SO4 +2H2O 2x40g. 98g. xg.
Correct answer: 46.5g NaOH- A. 50 g
- B. 72g
- C. 36g
- D. 54g
Explanation: This answer is incorrect because the number of moles of water produced is not 3.
Correct answer: 54g- A. CaCO3 is limiting reagent
- B. Both are consumed completely
- C. HCL is limiting reagent
- D. There is no reaction
Explanation: the equation for the reaction is CaCO3 + 2HCl → CO2 + H2O + CaCl2 Mr of HCl= 1 + 35.5 = 36.5 Mr of CaCO3= 40 + 12 + (3x16) = 100 2x36.5g…
Correct answer: CaCO3 is limiting reagent- A. When mole of H2O is produced
- B. All the oxygen is consumed
- C. 1.5 mole of NO is formed
- D. All the ammonia is consumed
Explanation: 4NH3 => 5O2 xNH3 => 1O2 x= 0.8mol As oxygen is the limiting factor it will be consumed first.
Correct answer: All the oxygen is consumed- A. Actual yield
- B. Percentage yield
- C. Theoratical yield
- D. None
Explanation: Theoretical yield is the maximum amount of product that can be obtained from a given amount of reactant, assuming that the reaction goes…
Correct answer: Theoratical yield- A. Some product is lost in the experiment
- B. Reversible reaction may occur
- C. Errors are madein 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. Side reactions may produce by product
- B. Some reactions are reversible
- C. Mechanical losss takes place due to 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. 22.4dm³
- B. 11.2dm³
- C. 44.8dm³
- D. None
Explanation: Volume = Moles x 22.4dm3 = 0.5 x 22.4 = 11.2dm³.
Correct answer: 11.2dm³- A. 4 moles of C
- B. Five moles of C
- C. 8 moles of C
- D. None of these
Explanation: The stoichiometric coefficients tell us the molar ratios between the reactants and products.
Correct answer: 4 moles of C- A. 55ml
- B. 58ml
- C. 70ml
- D. 79ml
Explanation: Following is the solution to this question:
Correct answer: 70ml- A. Chemical change
- B. Physical change
- C. Neither chemical nor physical change
- D. CO2 absorbed in Mg(C1O4)2
Explanation: Option a) "Chemical change" is correct because the absorption of CO2 in KOH solution involves a chemical reaction.
Correct answer: Chemical change- A. Side reactions
- B. Reversible nature
- C. Mechanical loss
- D. All of these
Explanation: Due to side reactions, reversible nature of reactions and mechanical loss, actual yield is less than theoretical yield.
Correct answer: All of these- A. 80 moles of atoms.
- B. 40 moles of hydrogen atom.
- C. 30 moles of electrons.
- D. 30 moles of oxygen atoms.
Explanation: 2H + O --> H2O H : H2O 2 : 1 X : 20 X=40 moles of hydrogen atom. (Correct)
Correct answer: 40 moles of hydrogen atom.- A. Is taken in lesser quantity in grams as compared to the other reactant
- B. Is taken in lesser quantity in volume as compared to the other reactant
- C. Gives the minimum amount of the product which is required
- D. Gives equal amounts of the reactants and products
Explanation: The limiting reactant (or limiting reagent) is the reactant that gets consumed first in a chemical reaction and therefore limits how much…
Correct answer: Gives the minimum amount of the product which is required- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The percent yield equation is: percent yield = actual yield / theoretical yield x 100% The percent yield is the ratio of the actual yield…
Correct answer: Option A- A. 120 ml
- B. 20 ml
- C. 40 ml
- D. 60 ml
Explanation: Following is the solution to this question:
Correct answer: 60 ml- A. 2 x 10^4 molecules
- B. 4 x 10^4 molecules
- C. 4 x 10^2 molecules
- D. None of these options is correct
Explanation: At the same temperature and pressure, equal volume of the gas contains equal number of molecules.
Correct answer: 4 x 10^4 molecules- A. Children usually ask this question why are eggs sold by the dozen.
- B. Children usually ask this question that why eggs are sold by the dozens.
- C. Children usually ask this question why eggs are sold by the dozen.
- D. Children usually ask this question why eggs are sold by dozen.
Explanation: The correct answer is C. Children usually ask this question why eggs are sold by the dozen.
Correct answer: Children usually ask this question why eggs are sold by the dozen.