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 28 of 45
- A. 1.0
- B. 4.50
- C. 0.50
- D. 0.25
Explanation: 1 mole of CO2 contains 16+16= 32g/mol of oxygen. By the proportion method, for the mass of oxygen to be decreased by 4 times to make it…
Correct answer: 0.25- A. H2O & H2O2
- B. C6H12 & C6H6
- C. H2S2O3 & H2SO4
- D. C6H12O6 & CH3COOH
Explanation: The Empirical formula is the formula, giving us the proportions of elements present in a compound.
Correct answer: C6H12O6 & CH3COOH- A. 6.02 x 10^23
- B. 6.02 x 10^24
- C. 6.02 x 10^22
- D. 3.01 x 10^23
Explanation: 1 mole of any substance contains Avogadro's number of particles which is 6.02 x 1023.
Correct answer: 6.02 x 10^23- A. 6.022 x 10^7
- B. 1.505 x 10^23
- C. 2.00 x 10^23
- D. 1.505 x 10^15
Explanation: As we know;No. of particles= mass/molar mass x NaOr,No. of particles= moles x Na= 0.25 x 6.02 × 1023= ¼ x 6.02 × 1023Hence, no.
Correct answer: 1.505 x 10^23- A. 1.7588 x 10^11 C
- B. 1.65 x 10^19 C
- C. 9.1095 x 10^-31 C
- D. 7.9 x 10^25 C
Explanation: This answer should be learnt due to unavailability of calculator in exam.
Correct answer: 1.7588 x 10^11 C- A. Hydrogen - 1.008
- B. Carbon - 12
- C. Carbon - 13
- D. Oxygen - 16
Explanation: The best standard for the calculation of relative atomic masses is based on the International Union of Pure and Applied Chemistry (IUPAC)…
Correct answer: Carbon - 12- A. 75.52 ; 24.47
- B. 49.20 ; 50.80
- C. 50.80 ; 49.20
- D. 60 ; 40
Explanation: This is a factual recall question.Bromine is a reddish-brown liquid belonging to group VII (halogens) of the periodic table and exists as…
Correct answer: 50.80 ; 49.20- A. 1 dm3 of molecule
- B. Mass of one molecule
- C. 1g of molecule
- D. 1g atom
- E. 1 mole
Explanation: Avogadro's number is the number of particles present in 1 mole of a substance.A mole is a unit of measurement used in chemistry to count…
Correct answer: 1 mole- A. 1
- B. 18
- C. 36
- D. 55.5
Explanation: Molarity is defined as the number of moles of the solute per liter of solution. We know that the density of water is 1g/ml or 1 Kg/ L.
Correct answer: 55.5- A. Is taken in a smaller quantity in grams as compared to the other reactant
- B. Is taken in a smaller quantity in volume as compared to the other reactant
- C. Limits the formation of the product by being consumed first
- D. Results in equal amounts of reactants and products
Explanation: The limiting reactant, or limiting reagent, is the reactant that is completely consumed first in a chemical reaction.
Correct answer: Limits the formation of the product by being consumed first551. The term which shows the quantitative relationship between the products and reactants is called as_?
- A. Percentage yield
- B. Stoichiometry
- C. Limiting reactant
- D. All of these
Explanation: Stoichiometry is a branch of chemistry in which quantitative relationship between masses of reactants and products are established.
Correct answer: Stoichiometry- A. Bar
- B. Centibar
- C. Millibar
- D. Kilobar
Explanation: The two most commonly used pressure units are the millibar and the inch of mercury - both of which are regularly used in broadcast…
Correct answer: Millibar- A. Dalton's law
- B. Avogadro's law
- C. Law of conservation of mass
- D. Law of conservation of energy
Explanation: Option A describes the law of partial pressures, which states that the total pressure by a mix of gases is equal to the sum of partial…
Correct answer: Law of conservation of mass- A. 1.75 mol
- B. 1750 mol
- C. 0.0175 mol
- D. 17.5 mol
Explanation: The molar mass of CaCO3 (40 + 12 + 16 + 16 + 16) is 100g per mole. If one mole equals 100g, than 1750g (1.75 kg x 1000) equals 1750/100…
Correct answer: 17.5 mol- A. 50 moles
- B. 100 moles
- C. 1000 moles
- D. 55.5 moles
Explanation: 1 mole of water corresponds to 18g. So, to calculate the number of moles of water in 1kg or 1000g of ice (NOTE: The state of the substance…
Correct answer: 55.5 moles- A. 1 M
- B. 0.5 M
- C. 0.25 M
- D. 2 M
Explanation: Molarity is moles of a substance divided by the volume in liters or cubic decimeters.
Correct answer: 1 M- A. 63.345amu
- B. 63.455amu
- C. 63.55amu
- D. 63.456amu
Explanation: It is a fact. The relative atomic mass of copper (Cu) is approximately 63.546.
Correct answer: 63.55amu- A. 6.022 x 10^23
- B. 3 x 6.022 x 10^23
- C. 2 x 6.022 x 10^23
- D. 4 x 6. 22 x 10^23
Explanation: 2 atoms of hydrogen are present in 18 gram of water.So it should be 2 6.022 x 1023To find the number of atoms of hydrogen in 18 grams of…
Correct answer: 2 x 6.022 x 10^23559. According to Avogadro's law, 0.899g of 1dm3 H2 and 1.4384g of 1dm3 O2 have _number of molecules.
- A. Same
- B. Different
- C. H2 has more
- D. O2 has more
Explanation: According to Avogadro's law, 0.899g of 1dm³ H₂ and 1.4384g of 1 dm³ of O₂ have the same number of molecules.
Correct answer: Same- A. 1417.53 g
- B. 2399.544 g
- C. 3456.78 g
- D. 1231.98 g
Explanation: We will use the formula, moles = mass / molecular massMolar mass of Ag2CO3= 275g/molNumber of moles = 8.694 molMass = moles x molar…
Correct answer: 2399.544 g